Could be several things.
Cheap memory. if it is pc133 rated set it to SPD or cas3 and try.
cheap motherboard.If this is a BX chipset motherboard you could be frying your videocard in the AGP slot. Few older cards could take 89mhz agp speed. .Also on BX boards ,not all motherboards fully support 133fsb/33pci so you could be overclocking the pci bus as well.
Raise the cpu core voltage by covering connectors A-119,B-119 and A-121 to get 2.2 volts.
IF these fail try setting the L2 cache from 8 to 9 or 10 with wcpul2 from <A HREF="http://www.H-ODA.com" target="_new">http://www.H-ODA.com</A>.
And last,few Katmai core processors run at 133fsb.This is due to the off die L2 cache. Good luck!!!
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