Ensure that disabled parts are actually disabled and removed.

src/main/java/appeng/items/parts/ItemMultiPart.java

@@ -155,7 +155,10 @@ public final class ItemMultiPart extends AEBaseItem implements IPartItem, IItemG
 			throw new IllegalStateException( "Meta Overlap detected with type " + mat + " and damage " + partDamage + ". Found " + registeredPartType + " there already." );
 		}
 
-		this.registered.put( partDamage, pti );
+		if( enabled )
+		{
+			this.registered.put( partDamage, pti );
+		}
 	}
 
 	public int getDamageByType( PartType t )
@@ -195,6 +198,11 @@ public final class ItemMultiPart extends AEBaseItem implements IPartItem, IItemG
 	@Override
 	public boolean onItemUse( ItemStack is, EntityPlayer player, World w, int x, int y, int z, int side, float hitX, float hitY, float hitZ )
 	{
+		if( this.getTypeByStack( is ) == PartType.InvalidType )
+		{
+			return false;
+		}
+
 		return AEApi.instance().partHelper().placeBus( is, x, y, z, side, player, w );
 	}
 
@@ -396,7 +404,6 @@ public final class ItemMultiPart extends AEBaseItem implements IPartItem, IItemG
 		}
 	}
 
-
 	private static final class RegisteredComparator implements Comparator<Entry<Integer, PartTypeWithVariant>>
 	{
 		@Override

src/main/java/appeng/items/parts/PartType.java

@@ -31,9 +31,9 @@ import appeng.integration.IntegrationType;
 import appeng.parts.automation.PartAnnihilationPlane;
 import appeng.parts.automation.PartExportBus;
 import appeng.parts.automation.PartFormationPlane;
+import appeng.parts.automation.PartIdentityAnnihilationPlane;
 import appeng.parts.automation.PartImportBus;
 import appeng.parts.automation.PartLevelEmitter;
-import appeng.parts.automation.PartIdentityAnnihilationPlane;
 import appeng.parts.misc.PartCableAnchor;
 import appeng.parts.misc.PartInterface;
 import appeng.parts.misc.PartInvertedToggleBus;