try setting AGP to 67, sometimes the default doesnt work.
your chip does seem to be hitting a wall a bit early, you may want to consider a modded bios like D26 Mantaray.
When you up the FSB and get a bluescreen try loosening the memory timings.
If it blue screens again then run the memory on a divider and try again.
to test stability run 8meg superpi when u are in windows as a quick test.
when u find a clock u are happy with run 32meg superpi, and a overnight prime95.
PS: Try 210x11
edit: what powersupply do you have, and what voltages/temperatures is it showing in windows, load and idle?