Cold boot problems at 270FSB on Abit IS7-G with P4 2.4C

[dp004i]

I'm having some trouble getting my comp to start up at 270FSB; it always gets stuck at the POST screen when cold-booting, never gets to the drive detection part. If I boot it up at lower FSB, change it to 270MHz in BIOS and do a warm reboot, it starts up just fine - runs prime95 for hours with no errors. What might be causing this problem? Could it be my power supply? It's an Antec True430, so it should be good enough. Memory is Kingston HyperX 4000, so I don't think that's the problem either.