try removing ExactModeTimingsDVI and adding NoHorizSyncCheck (one at a time, so you know which one fixes it, if any)
Edit: Actually, now that I think about it, the only time it gave the top 540 lines and not a black screen was when it was using the EDID nvidia-auto-select mode that it decided on. I don't think it's actually using the modeline you listed above. You really should do a 'startx -- -logverbose 6' and then look at /var/log/Xorg.0.log (or /var/log/XFree86.0.log) and see exactly what it's trying to do. I think it's actually rejecting your modeline and just picking one from EDID, which means you should try this line in your xorg.conf:
Option "ModeValidation" "AllowNon60HzDFPModes, NoVertRefreshCheck, NoEdidMaxPClkCheck, NoHorizSyncCheck"
and remove your ExactModeTimingsDVI line.
Last edited by pest_789; 11-22-06 at 12:43 PM.