Does anyone elses NF7-S ver 2 hang up when detecting drives???

When I change the FSB either higher or lower it will not detect drive in the begining of boot up. So I try try and try again until it boots and then its fine. I hate it!!!! What is the problem??? Its not hot and Im not pushing things to far at all. I have a brand new system except for my HD's. This happened to me when I got my last system 6 months ago with a NF7-M and a 1700 Cpu. I sent the mobo back and the one they sent back to me had a different cmos chip in it but i dont know anything else. Do I need to sent this one back too???
Has anyone else had this problem???

did you lock the PCI bus at 33Mhz? (agp at 66Mhz)

yeah, it was already locked. but all i have anyway is a vid card, but yeah it locked at 66mhz.