I had the same problem. I had 32 MB of ram and thought "just buy a stick of 512MB." I did, and when I put it in a figured out the board could only read up to 128MB SINGLE sided! Which meant that if it was a 128MB stick, but had 64MB on each side, it wouldn't work. Figured taht out the hard way too.
Evetually I bought two pc133 128MB SINGLE sided. They both clokced down to 66mhz (the mobo's FSB) perfectly.