diff --git a/src/main/java/refinedstorage/api/network/INetworkMaster.java b/src/main/java/refinedstorage/api/network/INetworkMaster.java
index 944d379b5..d69993930 100755
--- a/src/main/java/refinedstorage/api/network/INetworkMaster.java
+++ b/src/main/java/refinedstorage/api/network/INetworkMaster.java
@@ -11,7 +11,6 @@ import refinedstorage.api.autocrafting.ICraftingTask;
 import refinedstorage.api.storage.CompareFlags;
 
 import javax.annotation.Nullable;
-import java.util.Iterator;
 import java.util.List;
 
 public interface INetworkMaster {
@@ -54,9 +53,9 @@ public interface INetworkMaster {
     void update();
 
     /**
-     * @return A iterator with all network slaves
+     * @return A list with all network slaves, do NOT modify
      */
-    Iterator<INetworkSlave> getSlaves();
+    List<INetworkSlave> getSlaves();
 
     /**
      * @param slave The slave to add
diff --git a/src/main/java/refinedstorage/api/network/INetworkSlave.java b/src/main/java/refinedstorage/api/network/INetworkSlave.java
index 0ff509bab..f3fbfc74e 100755
--- a/src/main/java/refinedstorage/api/network/INetworkSlave.java
+++ b/src/main/java/refinedstorage/api/network/INetworkSlave.java
@@ -32,7 +32,7 @@ public interface INetworkSlave {
      *
      * @param world The world
      */
-    void onNeighborChanged(World world);
+    void refreshConnection(World world);
 
     /**
      * Called when a connection is found to the network
diff --git a/src/main/java/refinedstorage/apiimpl/network/NetworkMaster.java b/src/main/java/refinedstorage/apiimpl/network/NetworkMaster.java
index c0e54aa53..1011143c5 100755
--- a/src/main/java/refinedstorage/apiimpl/network/NetworkMaster.java
+++ b/src/main/java/refinedstorage/apiimpl/network/NetworkMaster.java
@@ -6,6 +6,7 @@ import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.nbt.NBTTagList;
+import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
 import net.minecraftforge.common.util.Constants;
@@ -58,6 +59,7 @@ public class NetworkMaster implements INetworkMaster {
     private List<IStorage> storages = new ArrayList<IStorage>();
 
     private List<BlockPos> slaves = new ArrayList<BlockPos>();
+    private List<INetworkSlave> actualSlaves = new ArrayList<INetworkSlave>();
     private Map<BlockPos, Boolean> slaveConnectivity = new HashMap<BlockPos, Boolean>();
     private List<BlockPos> slavesToAdd = new ArrayList<BlockPos>();
     private List<BlockPos> slavesToLoad = new ArrayList<BlockPos>();
@@ -150,11 +152,14 @@ public class NetworkMaster implements INetworkMaster {
 
     @Override
     public void update() {
+        boolean forceUpdate = !slavesToAdd.isEmpty() || !slavesToRemove.isEmpty();
+
         for (BlockPos slave : slavesToAdd) {
             if (!slaves.contains(slave)) {
                 slaves.add(slave);
             }
         }
+
         slavesToAdd.clear();
 
         slaves.removeAll(slavesToRemove);
@@ -163,14 +168,11 @@ public class NetworkMaster implements INetworkMaster {
         int lastEnergy = energy.getEnergyStored();
 
         if (canRun()) {
-            if (ticks % 20 == 0) {
+            if (ticks % 20 == 0 || forceUpdate) {
                 updateSlaves();
             }
 
-            Iterator<INetworkSlave> slaves = getSlaves();
-            while (slaves.hasNext()) {
-                INetworkSlave slave = slaves.next();
-
+            for (INetworkSlave slave : getSlaves()) {
                 if (slave.canUpdate()) {
                     slave.updateSlave();
                 }
@@ -196,11 +198,13 @@ public class NetworkMaster implements INetworkMaster {
             for (ICraftingTask task : craftingTasksToAdd) {
                 craftingTasks.push(task);
             }
+
             craftingTasksToAdd.clear();
 
             for (ICraftingTask task : craftingTasksToAddAsLast) {
                 craftingTasks.add(0, task);
             }
+
             craftingTasksToAddAsLast.clear();
 
             if (!craftingTasks.empty()) {
@@ -249,25 +253,8 @@ public class NetworkMaster implements INetworkMaster {
     }
 
     @Override
-    public Iterator<INetworkSlave> getSlaves() {
-        return new Iterator<INetworkSlave>() {
-            private int index;
-
-            @Override
-            public boolean hasNext() {
-                return index < slaves.size();
-            }
-
-            @Override
-            public INetworkSlave next() {
-                return world.getTileEntity(slaves.get(index++)).getCapability(RefinedStorageCapabilities.NETWORK_SLAVE_CAPABILITY, null);
-            }
-
-            @Override
-            public void remove() {
-                throw new UnsupportedOperationException();
-            }
-        };
+    public List<INetworkSlave> getSlaves() {
+        return actualSlaves;
     }
 
     @Override
@@ -295,13 +282,11 @@ public class NetworkMaster implements INetworkMaster {
     }
 
     public void disconnectAll() {
-        Iterator<INetworkSlave> slaves = getSlaves();
-
-        while (slaves.hasNext()) {
-            slaves.next().disconnect(world);
+        for (INetworkSlave slave : getSlaves()) {
+            slave.disconnect(world);
         }
 
-        this.slaves.clear();
+        slaves.clear();
     }
 
     @Override
@@ -402,14 +387,24 @@ public class NetworkMaster implements INetworkMaster {
 
     private void updateSlaves() {
         this.energyUsage = 0;
+        this.actualSlaves.clear();
         this.storages.clear();
         this.patterns.clear();
 
         int range = 0;
 
-        Iterator<INetworkSlave> slaves = getSlaves();
-        while (slaves.hasNext()) {
-            INetworkSlave slave = slaves.next();
+        for (BlockPos slavePos : slaves) {
+            TileEntity tile = world.getTileEntity(slavePos);
+
+            if (tile == null || !tile.hasCapability(RefinedStorageCapabilities.NETWORK_SLAVE_CAPABILITY, null)) {
+                removeSlave(slavePos);
+
+                continue;
+            }
+
+            INetworkSlave slave = tile.getCapability(RefinedStorageCapabilities.NETWORK_SLAVE_CAPABILITY, null);
+
+            actualSlaves.add(slave);
 
             if (!slave.canUpdate()) {
                 continue;
diff --git a/src/main/java/refinedstorage/block/BlockSlave.java b/src/main/java/refinedstorage/block/BlockSlave.java
index 810a3f87d..5a2a27693 100755
--- a/src/main/java/refinedstorage/block/BlockSlave.java
+++ b/src/main/java/refinedstorage/block/BlockSlave.java
@@ -43,7 +43,7 @@ public abstract class BlockSlave extends BlockBase {
         super.onBlockPlacedBy(world, pos, state, player, stack);
 
         if (!world.isRemote) {
-            ((TileSlave) world.getTileEntity(pos)).onNeighborChanged(world);
+            ((TileSlave) world.getTileEntity(pos)).refreshConnection(world);
         }
     }
 
@@ -65,7 +65,7 @@ public abstract class BlockSlave extends BlockBase {
         super.neighborChanged(state, world, pos, block);
 
         if (!world.isRemote) {
-            ((TileSlave) world.getTileEntity(pos)).onNeighborChanged(world);
+            ((TileSlave) world.getTileEntity(pos)).refreshConnection(world);
         }
     }
 }
diff --git a/src/main/java/refinedstorage/tile/TileSlave.java b/src/main/java/refinedstorage/tile/TileSlave.java
index 45e76006a..cdaaf5f9e 100755
--- a/src/main/java/refinedstorage/tile/TileSlave.java
+++ b/src/main/java/refinedstorage/tile/TileSlave.java
@@ -82,7 +82,7 @@ public abstract class TileSlave extends TileBase implements INetworkSlave, ISync
     }
 
     @Override
-    public void onNeighborChanged(World world) {
+    public void refreshConnection(World world) {
         TileController controller = searchController(world, pos, new HashSet<Long>());
 
         if (network == null) {
diff --git a/src/main/java/refinedstorage/tile/controller/TileController.java b/src/main/java/refinedstorage/tile/controller/TileController.java
index fdc4218c3..4a3c8328d 100755
--- a/src/main/java/refinedstorage/tile/controller/TileController.java
+++ b/src/main/java/refinedstorage/tile/controller/TileController.java
@@ -22,7 +22,6 @@ import refinedstorage.tile.config.IRedstoneModeConfig;
 import refinedstorage.tile.config.RedstoneMode;
 
 import java.util.ArrayList;
-import java.util.Iterator;
 import java.util.List;
 
 public class TileController extends TileBase implements IEnergyReceiver, ISynchronizedContainer, IRedstoneModeConfig {
@@ -151,10 +150,7 @@ public class TileController extends TileBase implements IEnergyReceiver, ISynchr
         if (getNetwork() != null) {
             List<ClientSlave> clientSlaves = new ArrayList<ClientSlave>();
 
-            Iterator<INetworkSlave> slaves = getNetwork().getSlaves();
-            while (slaves.hasNext()) {
-                INetworkSlave slave = slaves.next();
-
+            for (INetworkSlave slave : getNetwork().getSlaves()) {
                 if (slave.canUpdate()) {
                     IBlockState state = worldObj.getBlockState(slave.getPosition());
 
@@ -164,10 +160,11 @@ public class TileController extends TileBase implements IEnergyReceiver, ISynchr
                     clientSlave.amount = 1;
                     clientSlave.stack = new ItemStack(state.getBlock(), 1, state.getBlock().getMetaFromState(state));
 
-                    if (clientSlaves.contains(clientSlave)) {
+                    if (clientSlave.stack.getItem() != null && clientSlaves.contains(clientSlave)) {
                         for (ClientSlave other : clientSlaves) {
                             if (other.equals(clientSlave)) {
                                 other.amount++;
+
                                 break;
                             }
                         }