Server Crash w/Ultimate + Additional Mods

[vKILLZ0NEv]

Hey, I am trying to start a small server with some friends and I've tried adding a few other small mods to the Ultimate pack and I get a crash every time I start the server. I have worked the kinks out for SSP and it works fine there. I get a crash I don't recognize. Here are the mods I added, but I don't think it is a problem with them.

. Ropes Plus
. Easy Crafting
. Condensed Blocks
. Ars Magica
. Compact Solars
. Transformers

Think that's it.

Here's the crash:

[SEVERE] Encountered an unexpected exception NoSuchMethodError
java.lang.NoSuchMethodError: ModLoader.getMinecraftInstance()Lnet/minecraft/client/Minecraft;
at mod_InvTweaks.load(mod_InvTweaks.java:40)
at cpw.mods.fml.common.modloader.ModLoaderModContainer.init(ModLoaderModContainer.java:545)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:69)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:317)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:300)
at com.google.common.eventbus.EventBus.post(EventBus.java:268)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:153)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:69)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:317)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:300)
at com.google.common.eventbus.EventBus.post(EventBus.java:268)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:86)
at cpw.mods.fml.common.Loader.initializeMods(Loader.java:676)
at cpw.mods.fml.server.FMLServerHandler.finishServerLoading(FMLServerHandler.java:94)
at cpw.mods.fml.common.FMLCommonHandler.onServerStarted(FMLCommonHandler.java:356)
at ho.c(DedicatedServer.java:135)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:458)
at fy.run(SourceFile:849)

Thanks for any help!