Higher multipliers just quit working

I have had my Abit KD7-Raid and my 1700 Tbred B running just fine at 133x16.5 for a week or so and all of a sudden, i restarted the computer and it wont post now. So i did some troubleshooting and tried 100x16.5, and it still won't work. I played around with it, and none of the multipliers will work over 12.5, but last week they all worked. I havent done anything to make it change. I know you are probably thinking "why such a high multiplier, and not FSB" this is because I only have PC2100 ram, and this board won't let me run with the ram slower than the FSB. Any ideas??