Maybe try placing a downloaded config from the launcher, instead of letting RP make it.
Feed the Beast may have changed the IDs from the standard RP2 configs
Did, no worky. Tried updating Forge, no worky.[DOUBLEPOST=1360170393][/DOUBLEPOST]
Hi, I manage a different decently sized server on these forums, are you by chance running TickThreading?
I got this same error awhile back on my server running TickThreading.
TickThreading? Unless that's in the default Mindcrack pack; no.