Bizarre HyperX problem with 8rda+!

About 6 months ago I bought myself a nice stick of Kingston HyperX PC2700 512MB. Up until now it has been running perfect at its default speed (333mhz) but i was recently noticing a lack of FPS is several of my fav. online games so i figured i would overclock my computer.

First of all, when run with 166mhz fsb the memory reports no errors in memtest and runs flawlessly. Today though, when i went to 175mhz fsb the memory reports anywhere from 1000-90,000 errors in the last 2% of Test 5 in memtest. I have tried relaxing the timings, changing the seating of the ram chip and increasing the voltage. Every test scenario reported the same errors, no matter what i do. I cannot understand why though........ can 9mhz to the fsb make the memory that unstable? i was really hoping i could push 200mhz fsb....... but until i get some help - i don't think this will ever be possible.

i have an 8rda+ nforce2 mobo, athlon xp 2000, and a geforce3 ti200.

is there anything i can try?
has anyone had these kind of problems before?

i have narrowed it down to an incompatibility with my motherboard as it worked perfect at 180mhz fsb+ speeds in an abit nf7-s. is there a fix for the incompatibility with the hyperx ram in the 8rda+ or any obvious settings i could have set wrong?

under even further scrutiny i have found out that is i set my fsb to 200mhz but leave the memory at 166mhz i end up with the same errors in memtest.

this leads me to believe the RAM could possibly not be the culprit, but now, who is the culprit and how can i remedy it?

Could it be my low VDD which is only 1.58 volts?

any suggestions would be helpful