initializing network connections in tile entities' update function now (i.e. we call Network.joinOrCreateNetwork from there if we have a node and that node isn't in a network yet). this is because on block added is somewhat unreliable, in particular when other mods start getting involved - say, RIM. which is what I tested with right now, and it actually works, i.e. computers can be moved by carriages and keep running without fail. huzzah; also removed weak keys from screen renderer cache, the timeout is enough

li/cil/oc/client/renderer/tileentity/ScreenRenderer.scala

@@ -24,7 +24,6 @@ object ScreenRenderer extends TileEntitySpecialRenderer with Callable[Int] with
 
   /** We cache the display lists for the screens we render for performance. */
   val cache = com.google.common.cache.CacheBuilder.newBuilder().
-    weakKeys().
     expireAfterAccess(5, TimeUnit.SECONDS).
     removalListener(this).
     asInstanceOf[CacheBuilder[Screen, Int]].build[Screen, Int]()

li/cil/oc/common/block/Delegator.scala

@@ -4,8 +4,7 @@ import cpw.mods.fml.common.registry.GameRegistry
 import java.util
 import li.cil.oc.Config
 import li.cil.oc.CreativeTab
-import li.cil.oc.api.Network
+import li.cil.oc.api.network.Environment
-import li.cil.oc.api.network.{Environment, Node}
 import li.cil.oc.common.tileentity.Rotatable
 import net.minecraft.block.Block
 import net.minecraft.block.material.Material
@@ -290,13 +289,7 @@ class Delegator[Child <: Delegate](id: Int) extends Block(id, Material.iron) {
 
   override def onBlockAdded(world: World, x: Int, y: Int, z: Int) =
     subBlock(world, x, y, z) match {
-      case Some(subBlock) => {
+      case Some(subBlock) => subBlock.onBlockAdded(world, x, y, z)
-        world.getBlockTileEntity(x, y, z) match {
-          case _: Environment => Network.joinOrCreateNetwork(world, x, y, z)
-          case _ => // Nothing special to do.
-        }
-        subBlock.onBlockAdded(world, x, y, z)
-      }
       case _ => // Invalid but avoid match error.
     }
 

li/cil/oc/common/tileentity/Adapter.scala

@@ -2,6 +2,7 @@ package li.cil.oc.common.tileentity
 
 import dan200.computer.api.{ILuaContext, IComputerAccess, IPeripheral}
 import li.cil.oc.api
+import li.cil.oc.api.Network
 import li.cil.oc.api.network._
 import li.cil.oc.server
 import li.cil.oc.server.driver
@@ -25,6 +26,10 @@ class Adapter extends Rotatable with Environment with IPeripheral {
   // ----------------------------------------------------------------------- //
 
   override def updateEntity() {
+    super.updateEntity()
+    if (node != null && node.network == null) {
+      Network.joinOrCreateNetwork(worldObj, xCoord, yCoord, zCoord)
+    }
     for (block <- blocks) block match {
       case Some((environment, _)) => environment.update()
       case _ => // Empty.

li/cil/oc/common/tileentity/Computer.scala

@@ -1,6 +1,7 @@
 package li.cil.oc.common.tileentity
 
 import java.util.concurrent.atomic.AtomicBoolean
+import li.cil.oc.api.Network
 import li.cil.oc.api.driver.Slot
 import li.cil.oc.client.{PacketSender => ClientPacketSender}
 import li.cil.oc.server.component
@@ -60,7 +61,16 @@ class Computer(isClient: Boolean) extends Rotatable with ComputerEnvironment wit
 
   // ----------------------------------------------------------------------- //
 
-  override def updateEntity() = if (!worldObj.isRemote) {
+  override def updateEntity() {
+    super.updateEntity()
+    if (node != null && node.network == null) {
+      Network.joinOrCreateNetwork(worldObj, xCoord, yCoord, zCoord)
+    }
+    else if (!worldObj.isRemote) {
+      // If we just joined a network we were just loaded from disk. We skip the
+      // update this round to allow other tile entities to join the network,
+      // too, avoiding issues of missing nodes (e.g. in the GPU which would
+      // otherwise loose track of its screen).
       instance.update()
       updateRedstoneInput()
       if (hasChanged.get)
@@ -68,6 +78,7 @@ class Computer(isClient: Boolean) extends Rotatable with ComputerEnvironment wit
       if (isRunning != instance.isRunning)
         ServerPacketSender.sendComputerState(this, instance.isRunning)
       isRunning = instance.isRunning
+    }
 
     for (component <- components) component match {
       case Some(environment) => environment.update()
@@ -75,7 +86,7 @@ class Computer(isClient: Boolean) extends Rotatable with ComputerEnvironment wit
     }
   }
 
-  override def validate() = {
+  override def validate() {
     super.validate()
     if (worldObj.isRemote) {
       ClientPacketSender.sendComputerStateRequest(this)

li/cil/oc/common/tileentity/DiskDrive.scala

@@ -1,6 +1,7 @@
 package li.cil.oc.common.tileentity
 
 import li.cil.oc.api
+import li.cil.oc.api.Network
 import li.cil.oc.api.driver.Slot
 import li.cil.oc.api.network.{Component, Visibility}
 import li.cil.oc.server.driver.Registry
@@ -15,6 +16,15 @@ class DiskDrive extends Rotatable with Environment with ComponentInventory {
 
   // ----------------------------------------------------------------------- //
 
+  override def updateEntity() {
+    super.updateEntity()
+    if (node != null && node.network == null) {
+      Network.joinOrCreateNetwork(worldObj, xCoord, yCoord, zCoord)
+    }
+  }
+
+  // ----------------------------------------------------------------------- //
+
   override def readFromNBT(nbt: NBTTagCompound) {
     super.readFromNBT(nbt)
     if (node != null) node.load(nbt)

li/cil/oc/common/tileentity/Keyboard.scala

@@ -2,6 +2,7 @@ package li.cil.oc.common.tileentity
 
 import cpw.mods.fml.common.network.Player
 import li.cil.oc.api
+import li.cil.oc.api.Network
 import li.cil.oc.api.network.{Visibility, Message}
 import net.minecraft.entity.player.EntityPlayer
 import net.minecraft.nbt.NBTTagCompound
@@ -11,6 +12,16 @@ class Keyboard extends Rotatable with Environment {
     withComponent("keyboard").
     create()
 
+  // ----------------------------------------------------------------------- //
+
+  override def updateEntity() {
+    if (node != null && node.network == null) {
+      Network.joinOrCreateNetwork(worldObj, xCoord, yCoord, zCoord)
+    }
+  }
+
+  // ----------------------------------------------------------------------- //
+
   override def readFromNBT(nbt: NBTTagCompound) {
     super.readFromNBT(nbt)
     node.load(nbt)
@@ -21,6 +32,8 @@ class Keyboard extends Rotatable with Environment {
     node.save(nbt)
   }
 
+  // ----------------------------------------------------------------------- //
+
   override def onMessage(message: Message) = {
     message.data match {
       case Array(p: Player, char: Character, code: Integer) if message.name == "keyboard.keyDown" =>
@@ -37,6 +50,8 @@ class Keyboard extends Rotatable with Environment {
     super.onMessage(message)
   }
 
+  // ----------------------------------------------------------------------- //
+
   def isUseableByPlayer(p: Player) = worldObj.getBlockTileEntity(xCoord, yCoord, zCoord) == this &&
     p.asInstanceOf[EntityPlayer].getDistanceSq(xCoord + 0.5, yCoord + 0.5, zCoord + 0.5) < 64
 }

li/cil/oc/common/tileentity/PowerConverter.scala

@@ -4,6 +4,7 @@ import buildcraft.api.power.{PowerHandler, IPowerReceptor}
 import ic2.api.energy.event.{EnergyTileLoadEvent, EnergyTileUnloadEvent}
 import ic2.api.energy.tile.IEnergySink
 import li.cil.oc.api
+import li.cil.oc.api.Network
 import li.cil.oc.api.network._
 import net.minecraft.nbt.NBTTagCompound
 import net.minecraft.tileentity.TileEntity
@@ -37,6 +38,9 @@ class PowerConverter extends Rotatable with Environment with IEnergySink with IP
 
   override def updateEntity() {
     super.updateEntity()
+    if (node != null && node.network == null) {
+      Network.joinOrCreateNetwork(worldObj, xCoord, yCoord, zCoord)
+    }
     if (!worldObj.isRemote) {
       if (!addedToEnet) {
         MinecraftForge.EVENT_BUS.post(new EnergyTileLoadEvent(this))
@@ -62,14 +66,14 @@ class PowerConverter extends Rotatable with Environment with IEnergySink with IP
 
   // ----------------------------------------------------------------------- //
 
-  override def readFromNBT(nbt: NBTTagCompound) = {
+  override def readFromNBT(nbt: NBTTagCompound) {
     super.readFromNBT(nbt)
     node.load(nbt)
     getPowerProvider.readFromNBT(nbt)
 
   }
 
-  override def writeToNBT(nbt: NBTTagCompound) = {
+  override def writeToNBT(nbt: NBTTagCompound) {
     super.writeToNBT(nbt)
     node.save(nbt)
     getPowerProvider.writeToNBT(nbt)

li/cil/oc/common/tileentity/PowerDistributor.scala

@@ -1,6 +1,7 @@
 package li.cil.oc.common.tileentity
 
 import li.cil.oc.api
+import li.cil.oc.api.Network
 import li.cil.oc.api.network._
 import li.cil.oc.client.{PacketSender => ClientPacketSender}
 import li.cil.oc.server.network.Connector
@@ -23,6 +24,10 @@ class PowerDistributor extends Rotatable with Environment {
   // ----------------------------------------------------------------------- //
 
   override def updateEntity() {
+    super.updateEntity()
+    if (node != null && node.network == null) {
+      Network.joinOrCreateNetwork(worldObj, xCoord, yCoord, zCoord)
+    }
     if (!worldObj.isRemote && connectors.exists(_.dirty) && computeAverage()) {
       // Adjust buffer fill ratio for all buffers to average.
       connectors.foreach(c => c.buffer = c.bufferSize * average)

li/cil/oc/common/tileentity/Screen.scala

@@ -1,10 +1,11 @@
 package li.cil.oc.common.tileentity
 
 import li.cil.oc.Config
+import li.cil.oc.api.Network
 import li.cil.oc.api.network.Visibility
 import li.cil.oc.client.gui
 import li.cil.oc.client.{PacketSender => ClientPacketSender}
-import li.cil.oc.common.component
+import li.cil.oc.common.component.Screen.{Environment => ScreenEnvironment}
 import li.cil.oc.server.{PacketSender => ServerPacketSender}
 import net.minecraft.nbt.NBTTagCompound
 import net.minecraft.util.AxisAlignedBB
@@ -23,7 +24,7 @@ class ScreenTier3 extends Screen {
   protected def maxResolution = Config.screenResolutionsByTier(2)
 }
 
-abstract class Screen extends Rotatable with component.Screen.Environment {
+abstract class Screen extends Rotatable with ScreenEnvironment {
   var currentGui: Option[gui.Screen] = None
 
   /**
@@ -75,7 +76,7 @@ abstract class Screen extends Rotatable with component.Screen.Environment {
     super.save(nbt)
   }
 
-  override def validate() = {
+  override def validate() {
     super.validate()
     if (worldObj.isRemote) ClientPacketSender.sendScreenBufferRequest(this)
   }
@@ -89,7 +90,11 @@ abstract class Screen extends Rotatable with component.Screen.Environment {
 
   // ----------------------------------------------------------------------- //
 
-  override def updateEntity() =
+  override def updateEntity() {
+    super.updateEntity()
+    if (node != null && node.network == null) {
+      Network.joinOrCreateNetwork(worldObj, xCoord, yCoord, zCoord)
+    }
     if (shouldCheckForMultiBlock) {
       // Make sure we merge in a deterministic order, to avoid getting
       // different results on server and client due to the update order
@@ -142,6 +147,7 @@ abstract class Screen extends Rotatable with component.Screen.Environment {
         }
       )
     }
+  }
 
   def checkMultiBlock() {
     shouldCheckForMultiBlock = true