[hawk684]

I'm pretty sure I'm having the same issue.

I've got a Sony XBR1 TV hooked via DVI->HDMI from a GeForce 6800 on the 9620 driver and Ubuntu Edgy. I've got a custom modeline that underscan's just right and worked fine on the previous driver (8776).

Xorg.log.0

(--) NVIDIA(0): Connected display device(s) on GeForce 6800 at PCI:1:0:0:
(--) NVIDIA(0):     DFP-0
(--) NVIDIA(0): DFP-0: 155.0 MHz maximum pixel clock
(--) NVIDIA(0): DFP-0: Internal Single Link TMDS
(II) NVIDIA(0): Assigned Display Device: DFP-0
(WW) NVIDIA(0): No valid modes for "ATSC720"; removing.
(WW) NVIDIA(0):
(WW) NVIDIA(0): Unable to validate any modes; falling back to the default mode
(WW) NVIDIA(0):     "nvidia-auto-select".
(WW) NVIDIA(0):
(II) NVIDIA(0): Validated modes:
(II) NVIDIA(0):     "nvidia-auto-select"
(II) NVIDIA(0): Virtual screen size determined to be 640 x 480

Xorg.conf

Section "Device"
        Identifier      "NVIDIA Corporation NV41.1 [GeForce 6800]"
        Driver          "nvidia"
        BusID           "PCI:1:0:0"
        Option          "RandRRotation" "on"
#       Option          "ConnectedMonitor" "DFP"
#       Option          "IgnoreEDID" "True"
        Option          "UseEDID" "False"
        Option          "ModeValidation" "NoEdidDFPMaxSizeCheck"
EndSection

Section "Monitor"
        Identifier      "SONY TV"
        #Option         "DPMS"
        ModeLine "ATSC720" 74.25 1218 1358 1376 1650 676 710 750 752 +hsync
        ModeLine "ATSC-720-59.94p" 74.176 1280 1320 1376 1650 720 722 728 750
        DisplaySize             320 180
EndSection

Section "Screen"
        Identifier      "Default Screen"
        Device          "NVIDIA Corporation NV41.1 [GeForce 6800]"
        Monitor         "SONY TV"
        DefaultDepth    24
        Option         "NvAGP" "0"
        Option         "NoLogo" "False"
        Option         "ConnectedMonitor" "DFP"
        Option         "ExactModeTimingsDVI" "True"
        Option          "AddARGBGLXVisuals" "True"
        SubSection     "Display"
                Depth       24
                Modes      "ATSC720"
        EndSubSection
EndSection

What it looks like is for some reason the driver is no longer seeing custom modelines, as if Option "ModeValidation" "NoXServerModes" was persistently turned on or something like that. Unfortunately because HDTV's are flaky I need that bizarre ATSC720 custom modeline if I want to not have any overscan. I'd use the older drivers but I had trouble with them and Beryl working correctly