Force a global asset scan prior to mod construction : you should be able to

reference assets anywhere in your mod now.

fml/client/cpw/mods/fml/client/FMLClientHandler.java

@@ -585,4 +585,10 @@ public class FMLClientHandler implements IFMLSidedHandler
             }
         }
     }
+
+    @Override
+    public void updateResourcePackList()
+    {
+        client.func_110436_a();
+    }
 }

fml/common/cpw/mods/fml/common/FMLCommonHandler.java

@@ -491,4 +491,9 @@ public class FMLCommonHandler
     {
         sidedDelegate.addModAsResource(container);
     }
+
+    public void updateResourcePackList()
+    {
+        sidedDelegate.updateResourcePackList();
+    }
 }

fml/common/cpw/mods/fml/common/IFMLSidedHandler.java

@@ -64,4 +64,6 @@ public interface IFMLSidedHandler
     void disconnectIDMismatch(MapDifference<Integer, ItemData> s, NetHandler toKill, INetworkManager mgr);
 
     void addModAsResource(ModContainer container);
+
+    void updateResourcePackList();
 }

fml/common/cpw/mods/fml/common/LoadController.java

@@ -95,6 +95,7 @@ public class LoadController
         }
 
         eventChannels = eventBus.build();
+        FMLCommonHandler.instance().updateResourcePackList();
     }
 
     public void distributeStateMessage(LoaderState state, Object... eventData)

fml/common/cpw/mods/fml/server/FMLServerHandler.java

@@ -195,4 +195,9 @@ public class FMLServerHandler implements IFMLSidedHandler
     {
         // NOOP on server
     }
+    @Override
+    public void updateResourcePackList()
+    {
+        // NOOP on server
+    }
 }