Comp crashes as 166FSB

Wow, 2 computers that I can't figure out what's wrong with then in as many days. I'm really losing my touch. Ok, this computer crashes whenever I set the FSB to 166. It will run for maybe 5-15 minutes and then either blue screen, or just crash to desktop. In either case, all it gives is a generic 'Windows doesn't know what happened' error. Setting the FSB to 100 or 133 it runs fine all day long. The mobo is a MSI K7N2 Delta-L, processor is Athlon XP 2700+ and both are rated to support 166. Heck, even the memory is 166 (333, whatever). Any ideas?

Take note that there is a version of the 2700+ that uses a 133 fsb, it just depends on the core.  The early versions of the chip used 133 while they uped it to 166 later.  So it could be that you have an earlier revision of the chip.