Ram holding me back?

I've got a kt-400 plat board and Samsung ram. Got it up to 166 fst anything higher then that system becomes unstable no matter how many volts I put to it. I was wondering if anyone else has tried Crucial Micron pc 3200 or higher on this board and if so what were your results?

The highest I was able to hit comfortably on my board was 169*13 @1.775v with my generic samsung PC2100. I got the board stable at 172*13 with the same ram, but the temps were unreasonable, so I backed off.
Ever since I got WinXP to install finally my FSB settings have given stability issues. Right now I am stuck at 148*13.5 @1.65v, any higher and Seti @home shuts down at random intervals. I got it running with WinXp at 164*13, but Seti crashed out within a few mins.

The strange thing is that Seti will crash out but windows stays running and does not lock up.

I know this board is picky on the RAM. I haven't got above 170 so far.