I don't know if Rev. C ROMs fixed this problem, but ISTR that if the system resides in a partition larger than 8GB, much flakiness can occur if any system resources are stored beyond the 8GB limit. Perhaps this is irrelevant (and maybe even wrong altogether; I'd always partitioned my G3 drives to avoid even the possibility of such problems, so I'm relying on what I'd heard from others), but I'm passing it on FWIW.