When using knfsd a RH 6.0 alpha LX164 system, kernel 2.2.10 (tested with older kernels too) gets unstable, but its hard to notice. to reproduce, try kernel compiles, they will fail with gcc SIGSEGV while knfs is used !!when compiling on a LOCAL filesystem, and not using nfs at all!!. The module seems to be enough to destabilize the system. removing knfs and reverting to nfs-server from RH5.2 fixes the problems.
Try the latest knfsd-1.4.7-2 and kernel-2.2.11-4 from Raw Hide. Does that fix your problem?
Way too old by now, will try again when we finally get a pinstripe for Alpha