[netllama]

According to your bug report, I see:
(II) NVIDIA(0): Validated modes:
(II) NVIDIA(0): "1280x1024"
(II) NVIDIA(0): "1280x960"
(II) NVIDIA(0): "1280x800"
(II) NVIDIA(0): "1152x864"
(II) NVIDIA(0): "1280x768"
(II) NVIDIA(0): "1024x768"
(II) NVIDIA(0): "1280x600"
(II) NVIDIA(0): "1024x600"
(II) NVIDIA(0): "800x600"
(II) NVIDIA(0): "768x576"
(II) NVIDIA(0): "640x480"

You didn't say how you were trying to change modes, however if the display is reporting that nothing other than 1280x1024 works, then that isn't a driver problem, its a display problem.

It would be worthwhile to remove all the modelines in your xorg.conf, as they shouldn't normally be needed, and could potentially be incorrect.

Thanks,
Lonni