can't get pass 2.4ghz w/ a 2100+ (2700+ wiremod)

well, the topic saids it all. I can't seem to boot to windows xp w/o bluecsreening at startup when i try to go 2.4ghz and over. I could do it w/ my epox 8rda+. I even tried 200fsb x 12 and it still won't boot, even w/ 1.85vcore,2.9vdimm,1.7v chipset and optimal ram settings. I did a wire mod for my 2100+ to make it 166fsb default. Anyone know wat could be wrong??