diff --git a/parts/CableBusContainer.java b/parts/CableBusContainer.java
index 4b4da71bc..4741c3dde 100644
--- a/parts/CableBusContainer.java
+++ b/parts/CableBusContainer.java
@@ -21,6 +21,7 @@ import net.minecraft.util.Vec3;
 import net.minecraft.world.World;
 import net.minecraftforge.common.util.ForgeDirection;
 import appeng.api.AEApi;
+import appeng.api.config.YesNo;
 import appeng.api.exceptions.FailedConnection;
 import appeng.api.implementations.parts.IPartCable;
 import appeng.api.networking.IGridHost;
@@ -57,7 +58,7 @@ public class CableBusContainer implements AEMultiTile, ICableBusContainer
 	private FacadeContainer fc = new FacadeContainer();
 	private EnumSet<LayerFlags> myLayerFlags = EnumSet.noneOf( LayerFlags.class );
 
-	public boolean hasRedstone = false;
+	public YesNo hasRedstone = YesNo.UNDECIDED;
 	public IPartHost tcb;
 
 	boolean inWorld = false;
@@ -336,7 +337,6 @@ public class CableBusContainer implements AEMultiTile, ICableBusContainer
 		isLoading.set( true );
 
 		TileEntity te = getTile();
-		hasRedstone = te.getWorldObj().isBlockIndirectlyGettingPowered( te.xCoord, te.yCoord, te.zCoord );
 
 		// start with the center, then install the side parts into the grid.
 		for (int x = 6; x >= 0; x--)
@@ -492,7 +492,7 @@ public class CableBusContainer implements AEMultiTile, ICableBusContainer
 	public void onNeighborChanged()
 	{
 		TileEntity te = getTile();
-		hasRedstone = te.getWorldObj().isBlockIndirectlyGettingPowered( te.xCoord, te.yCoord, te.zCoord );
+		hasRedstone = YesNo.UNDECIDED;
 
 		for (ForgeDirection s : ForgeDirection.values())
 		{
@@ -502,6 +502,12 @@ public class CableBusContainer implements AEMultiTile, ICableBusContainer
 		}
 	}
 
+	private void updateRedstone()
+	{
+		TileEntity te = getTile();
+		hasRedstone = te.getWorldObj().isBlockIndirectlyGettingPowered( te.xCoord, te.yCoord, te.zCoord ) ? YesNo.YES : YesNo.NO;
+	}
+
 	public boolean isSolidOnSide(ForgeDirection side)
 	{
 		if ( side == null || side == ForgeDirection.UNKNOWN )
@@ -637,6 +643,8 @@ public class CableBusContainer implements AEMultiTile, ICableBusContainer
 
 	public void writeToNBT(NBTTagCompound data)
 	{
+		data.setInteger( "hasRedstone", hasRedstone.ordinal() );
+
 		for (ForgeDirection s : ForgeDirection.values())
 		{
 			fc.writeToNBT( data );
@@ -658,6 +666,9 @@ public class CableBusContainer implements AEMultiTile, ICableBusContainer
 
 	public void readFromNBT(NBTTagCompound data)
 	{
+		if ( data.hasKey( "hasRedstone" ) )
+			hasRedstone = YesNo.values()[data.getInteger( "hasRedstone" )];
+
 		for (int x = 0; x < 7; x++)
 		{
 			ForgeDirection side = ForgeDirection.getOrientation( x );
@@ -921,7 +932,10 @@ public class CableBusContainer implements AEMultiTile, ICableBusContainer
 	@Override
 	public boolean hasRedstone(ForgeDirection side)
 	{
-		return hasRedstone;
+		if ( hasRedstone == YesNo.UNDECIDED )
+			updateRedstone();
+
+		return hasRedstone == YesNo.YES;
 	}
 
 	public boolean isLadder(EntityLivingBase entity)
diff --git a/parts/misc/PartToggleBus.java b/parts/misc/PartToggleBus.java
index d9ca8a11e..06ec0d15e 100644
--- a/parts/misc/PartToggleBus.java
+++ b/parts/misc/PartToggleBus.java
@@ -103,6 +103,7 @@ public class PartToggleBus extends PartBasicState
 	{
 		super.addToWorld();
 		outerProxy.onReady();
+		hasRedstone = getHost().hasRedstone( side );
 		updateInternalState();
 	}
 
diff --git a/parts/p2p/PartP2PLight.java b/parts/p2p/PartP2PLight.java
index c82cb0536..e6cf72cb4 100644
--- a/parts/p2p/PartP2PLight.java
+++ b/parts/p2p/PartP2PLight.java
@@ -35,6 +35,7 @@ public class PartP2PLight extends PartP2PTunnel<PartP2PLight> implements IGridTi
 	}
 
 	int lastValue = 0;
+	float opacity = -1;
 
 	public void setLightLevel(int out)
 	{
@@ -53,8 +54,12 @@ public class PartP2PLight extends PartP2PTunnel<PartP2PLight> implements IGridTi
 
 	private int blockLight(int emit)
 	{
-		TileEntity te = this.getTile();
-		float opacity = 255 - te.getWorldObj().getBlockLightOpacity( te.xCoord + side.offsetX, te.yCoord + side.offsetY, te.zCoord + side.offsetZ );
+		if ( opacity < 0 )
+		{
+			TileEntity te = this.getTile();
+			opacity = 255 - te.getWorldObj().getBlockLightOpacity( te.xCoord + side.offsetX, te.yCoord + side.offsetY, te.zCoord + side.offsetZ );
+		}
+
 		return (int) (emit * (opacity / 255.0f));
 	}
 
@@ -96,7 +101,10 @@ public class PartP2PLight extends PartP2PTunnel<PartP2PLight> implements IGridTi
 	@Override
 	public void onNeighborChanged()
 	{
+		opacity = -1;
+
 		doWork();
+
 		if ( output )
 			getHost().markForUpdate();
 	}
@@ -105,6 +113,7 @@ public class PartP2PLight extends PartP2PTunnel<PartP2PLight> implements IGridTi
 	public void writeToNBT(NBTTagCompound tag)
 	{
 		super.writeToNBT( tag );
+		tag.setFloat( "opacity", opacity );
 		tag.setInteger( "lastValue", lastValue );
 	}
 
@@ -112,6 +121,8 @@ public class PartP2PLight extends PartP2PTunnel<PartP2PLight> implements IGridTi
 	public void readFromNBT(NBTTagCompound tag)
 	{
 		super.readFromNBT( tag );
+		if ( tag.hasKey( "opacity" ) )
+			opacity = tag.getFloat( "opacity" );
 		lastValue = tag.getInteger( "lastValue" );
 	}
 
diff --git a/parts/reporting/PartMonitor.java b/parts/reporting/PartMonitor.java
index bf4c8e49d..2971df430 100644
--- a/parts/reporting/PartMonitor.java
+++ b/parts/reporting/PartMonitor.java
@@ -44,6 +44,7 @@ public class PartMonitor extends AEBasePart implements IPartMonitor, IPowerChann
 
 	byte spin = 0; // 0-3
 	int clientFlags = 0; // sent as byte.
+	float opacity = -1;
 
 	@Override
 	public void onPlacement(EntityPlayer player, ItemStack held, ForgeDirection side)
@@ -61,6 +62,7 @@ public class PartMonitor extends AEBasePart implements IPartMonitor, IPowerChann
 	public void writeToNBT(NBTTagCompound data)
 	{
 		super.writeToNBT( data );
+		data.setFloat( "opacity", opacity );
 		data.setByte( "spin", (byte) spin );
 	}
 
@@ -68,6 +70,8 @@ public class PartMonitor extends AEBasePart implements IPartMonitor, IPowerChann
 	public void readFromNBT(NBTTagCompound data)
 	{
 		super.readFromNBT( data );
+		if ( data.hasKey( "opacity" ) )
+			opacity = data.getFloat( "opacity" );
 		spin = data.getByte( "spin" );
 	}
 
@@ -118,6 +122,7 @@ public class PartMonitor extends AEBasePart implements IPartMonitor, IPowerChann
 	@Override
 	public void onNeighborChanged()
 	{
+		opacity = -1;
 		getHost().markForUpdate();
 	}
 
@@ -173,8 +178,12 @@ public class PartMonitor extends AEBasePart implements IPartMonitor, IPowerChann
 
 	private int blockLight(int emit)
 	{
-		TileEntity te = this.getTile();
-		float opacity = 255 - te.getWorldObj().getBlockLightOpacity( te.xCoord + side.offsetX, te.yCoord + side.offsetY, te.zCoord + side.offsetZ );
+		if ( opacity < 0 )
+		{
+			TileEntity te = this.getTile();
+			opacity = 255 - te.getWorldObj().getBlockLightOpacity( te.xCoord + side.offsetX, te.yCoord + side.offsetY, te.zCoord + side.offsetZ );
+		}
+
 		return (int) (emit * (opacity / 255.0f));
 	}
 
diff --git a/tile/spatial/TileSpatialIOPort.java b/tile/spatial/TileSpatialIOPort.java
index df90749cf..70762de40 100644
--- a/tile/spatial/TileSpatialIOPort.java
+++ b/tile/spatial/TileSpatialIOPort.java
@@ -4,9 +4,11 @@ import java.util.concurrent.Callable;
 
 import net.minecraft.inventory.IInventory;
 import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.NBTTagCompound;
 import net.minecraftforge.common.util.ForgeDirection;
 import appeng.api.config.Actionable;
 import appeng.api.config.PowerMultiplier;
+import appeng.api.config.YesNo;
 import appeng.api.implementations.TransitionResult;
 import appeng.api.implementations.items.ISpatialStorageCell;
 import appeng.api.networking.GridFlags;
@@ -20,6 +22,8 @@ import appeng.api.util.DimensionalCoord;
 import appeng.hooks.TickHandler;
 import appeng.items.storage.ItemSpatialStorageCell;
 import appeng.me.cache.SpatialPylonCache;
+import appeng.tile.events.AETileEventHandler;
+import appeng.tile.events.TileEventType;
 import appeng.tile.grid.AENetworkInvTile;
 import appeng.tile.inventory.AppEngInternalInventory;
 import appeng.tile.inventory.InvOperation;
@@ -30,25 +34,53 @@ public class TileSpatialIOPort extends AENetworkInvTile implements Callable
 
 	final int sides[] = { 0, 1 };
 	AppEngInternalInventory inv = new AppEngInternalInventory( this, 2 );
-	boolean lastRedstoneState = false;
+	YesNo lastRedstoneState = YesNo.UNDECIDED;
+
+	class SpatialTileIOPortHandler extends AETileEventHandler
+	{
+
+		public SpatialTileIOPortHandler() {
+			super( TileEventType.WORLD_NBT );
+		}
+
+		@Override
+		public void writeToNBT(NBTTagCompound data)
+		{
+			data.setInteger( "lastRedstoneState", lastRedstoneState.ordinal() );
+		}
+
+		@Override
+		public void readFromNBT(NBTTagCompound data)
+		{
+			if ( data.hasKey( "lastRedstoneState" ) )
+				lastRedstoneState = YesNo.values()[data.getInteger( "lastRedstoneState" )];
+		}
+	};
 
 	public TileSpatialIOPort() {
+		addNewHandler( new SpatialTileIOPortHandler() );
 		gridProxy.setFlags( GridFlags.REQUIRE_CHANNEL );
 	}
 
 	public void updateRedstoneState()
 	{
-		boolean currentState = worldObj.isBlockIndirectlyGettingPowered( xCoord, yCoord, zCoord );
+		YesNo currentState = worldObj.isBlockIndirectlyGettingPowered( xCoord, yCoord, zCoord ) ? YesNo.YES : YesNo.NO;
 		if ( lastRedstoneState != currentState )
 		{
 			lastRedstoneState = currentState;
-			if ( currentState )
-			{
+			if ( lastRedstoneState == YesNo.YES )
 				triggerTransition();
-			}
 		}
 	}
 
+	public boolean getRedstoneState()
+	{
+		if ( lastRedstoneState == YesNo.UNDECIDED )
+			updateRedstoneState();
+
+		return lastRedstoneState == YesNo.YES;
+	}
+
 	private void triggerTransition()
 	{
 		if ( Platform.isServer() )
@@ -81,7 +113,7 @@ public class TileSpatialIOPort extends AENetworkInvTile implements Callable
 				if ( Math.abs( pr - req ) < req * 0.001 )
 				{
 					MENetworkEvent res = gi.postEvent( new MENetworkSpatialEvent( this, req ) );
-					if ( ! res.isCanceled() )
+					if ( !res.isCanceled() )
 					{
 						TransitionResult tr = sc.doSpatialTransition( cell, worldObj, spc.getMin(), spc.getMax(), true );
 						if ( tr.success )
diff --git a/tile/storage/TileIOPort.java b/tile/storage/TileIOPort.java
index cc01397a9..8adebd5c7 100644
--- a/tile/storage/TileIOPort.java
+++ b/tile/storage/TileIOPort.java
@@ -11,6 +11,7 @@ import appeng.api.config.OperationMode;
 import appeng.api.config.RedstoneMode;
 import appeng.api.config.Settings;
 import appeng.api.config.Upgrades;
+import appeng.api.config.YesNo;
 import appeng.api.implementations.IUpgradeableHost;
 import appeng.api.networking.GridFlags;
 import appeng.api.networking.IGridNode;
@@ -59,7 +60,7 @@ public class TileIOPort extends AENetworkInvTile implements IUpgradeableHost, IC
 
 	BaseActionSource mySrc = new MachineSource( this );
 
-	boolean lastRedstoneState = false;
+	YesNo lastRedstoneState = YesNo.UNDECIDED;
 
 	class TileIOPortHandler extends AETileEventHandler
 	{
@@ -74,6 +75,7 @@ public class TileIOPort extends AENetworkInvTile implements IUpgradeableHost, IC
 			cm.writeToNBT( data );
 			cells.writeToNBT( data, "cells" );
 			upgrades.writeToNBT( data, "upgrades" );
+			data.setInteger( "lastRedstoneState", lastRedstoneState.ordinal() );
 		}
 
 		@Override
@@ -82,6 +84,8 @@ public class TileIOPort extends AENetworkInvTile implements IUpgradeableHost, IC
 			cm.readFromNBT( data );
 			cells.readFromNBT( data, "cells" );
 			upgrades.readFromNBT( data, "upgrades" );
+			if ( data.hasKey( "lastRedstoneState" ) )
+				lastRedstoneState = YesNo.values()[data.getInteger( "lastRedstoneState" )];
 		}
 	};
 
@@ -137,7 +141,7 @@ public class TileIOPort extends AENetworkInvTile implements IUpgradeableHost, IC
 
 	public void updateRedstoneState()
 	{
-		boolean currentState = worldObj.isBlockIndirectlyGettingPowered( xCoord, yCoord, zCoord );
+		YesNo currentState = worldObj.isBlockIndirectlyGettingPowered( xCoord, yCoord, zCoord ) ? YesNo.YES : YesNo.NO;
 		if ( lastRedstoneState != currentState )
 		{
 			lastRedstoneState = currentState;
@@ -145,6 +149,14 @@ public class TileIOPort extends AENetworkInvTile implements IUpgradeableHost, IC
 		}
 	}
 
+	public boolean getRedstoneState()
+	{
+		if ( lastRedstoneState == YesNo.UNDECIDED )
+			updateRedstoneState();
+
+		return lastRedstoneState == YesNo.YES;
+	}
+
 	private boolean isEnabled()
 	{
 		if ( getInstalledUpgrades( Upgrades.REDSTONE ) == 0 )
@@ -152,8 +164,8 @@ public class TileIOPort extends AENetworkInvTile implements IUpgradeableHost, IC
 
 		RedstoneMode rs = (RedstoneMode) cm.getSetting( Settings.REDSTONE_CONTROLLED );
 		if ( rs == RedstoneMode.HIGH_SIGNAL )
-			return lastRedstoneState;
-		return !lastRedstoneState;
+			return getRedstoneState();
+		return !getRedstoneState();
 	}
 
 	@Override