Yes I have the VID issue too with the QX9650, had it too with the P5K and P5Q Dlx boards...

Best suitable on my board is 9 X 450FSB and 4GB 1800mhz C7on the Rams. I use strap 333 and clock twister light to reduce the stress on the NB. If I go over 450FSB I need to lower the ram clocks to remain stable and use strap 400. But this REX's NB isn't the best... too bad my good one went down...