It shouldnt
> say there's at least a 99% chance it's turned off. Is it possible some
> other random kernel bug is at fault?
No. An NMI is an NMI. NMI is used on older boxes to flag memory faults. On
newer systems it is sometimes used for power saving (hence the newer
message). The odds of accidentally jumping into the NMI handler are
pretty close to NIL
> The system this one replaced used to get occasional page table or swap
> corruption, and people suggested it could be bad RAM. It's been running
> memtest86 for over a week and done 143 passes with 0 errors.
memtest86 won't find all memory bugs. However if this is a totally new
machine it is indeed curious