Have you tried injecting your vbios from ioreg that was working under 10.6.1 or 10.6.2 into NVEnabler64?
You may get better results, it could be NVCAP issues.
Here for what is worth is my NVEnabler with edited info.plist, but it was generated under 10.6.4
Thank you very much for NVEnabler_64.kext.zip
I have 10.6.4 Retail
- MB: GA-p55-us3l
- Video: asus 9800gt (id 0x0605)
NVEnabler_64.kext placed in the E / E
DVI-HDMI works perfectly.