hey I've get the same error as fewizz.
I'm using a headless/dedicated server.
tried both forge server and cauldron server and got the same error
claudron log http://pastebin.com/6kGizVUK
forge log http://pastebin.com/UuZvHYf0
cauldron verison is:1.7.10-1.1207.01.183
and forge is:1.7.10-10.13.0.1207
ic:industrialcraft-2-2.2.597-experimental
turbo: 1.7.10-1.2.0
biomaterials: 1.7.10-4.1.0
if more info needed, just say so 
cheers
edit: remove all mods execpt essential ones, still crashes, same error
forge log: http://pastebin.com/uvWA0MGQ
cauldron log: http://pastebin.com/BfKbPGBr