The only time i found something similar was when you got hit and lose HP you would fall as if there was no gravity.
Post that bug report in the new bug thing, it changed since you made this thread.
If micdoodle8 allow's people to distribute addons at this moment the only things you need to make addons is to know how to mod with forge and then integrate with GC's API.(Assuming the API is ready to be used).
You should also get to know universal electricity,mekanism,icbm for better results...
Close minecraft so you can open .lck safelly.
Open ForgeModLoader-Client-0.log ( with notepad for examaple) and put the whole thing on http://pastebin.com/ or something like that.
I have had that kind of problems but on my case it way my computer messing things ( bad graphic drivers).
Could you post the Error Report?
It's the file named ForgeModLoader-client-0.log in your minecraft folder.
CodeChickenCore [CodeChicken Core]
This is part (shared part,that goes into coremods) of the Better World Generation mod which also crashed.(thread about similar issue)
No idea about what could be causing this..
Yup.
Its a 2013-03-28 21:08:52 [INFO] [STDERR] java.lang.NoSuchMethodError: net.minecraft.world.gen.layer.GenLayer.func_75901_a(JLnet/minecraft/world/WorldType;)[Lnet/minecraft/world/gen/layer/GenLayer;
Then Forge panics.
Actually i didn't install the mod right ( fail , my head just went "forge -> lets put in mods folder and forget about those readme's").
Will test again...
and...
It's a crash...
Strangely i just installed that mod and went to the moon on a fresh world and nothing crashed.
I just have this feeling that ...
2013-03-28 00:37:59 [SEVERE] [ForgeModLoader] The ForgeModLoader state engine has become corrupted. Probably, a state was missed by and invalid modification to a...