Filter out FEATURES="distcc" with FEATURES="-distcc" for nvidia-kernel please, it breaks it. I went back and fort testing this, it is distcc.
Care to be a little more verbose in your claim? Such as, post what fails and how it fails?
the nvidia kernel gets the GLOBAL_OFFSET_TABLE, __guard, and __stack_smash_handler symbols. This in itself happens with or without distcc; however, when using distcc, for some reason loading the module spits out these three symbols as "Unresolved symbols." I haven't found exactly why; distcc supposedly preprocesses on the client side, so it shouldn't be kernel header problems.
Which versions of the nvidia-kernel are effected? Are you using the same GCC versions on all volunteer machines? Are you using hardened-gcc on any machine?
still waiting for info...