SB51G memory divider?

[major_major]

Hi, i'm running a p4 1.6a in a shuttle sb51G and i'm using pc2100 ram. My problem is that the bios doesn't seem to have an option to let me run the ram at a 1:1 ratio. Therefore, i'm forced to run it at 133mhz which makes overclocking quite difficult since any increase in FSB pushes the ram past its rated speed. The shuttle manual suggests that there is a way to choose memory ratios, but the bios is very limited and 133 is the slowest it'll let me run my ram. Can anybody offer any suggestions?