Tv-Out overscan compensation: "Unable to support custom viewPortOut" w/ 340.58

I am using a GeForce 8500GT with a CRT television connected via svideo. I notice the overscan option has been removed from the driver in the current versions, and replaced with ViewPort[In|Out]. Regardless of the underscan setting using the nvidia-settings gui, the TV output remains at maximum overscan and renders the desktop unusable. Here is the relevant line from the xorg.conf file

Option         "metamodes" "1024x768 +0+0 {viewportout=926x694+49+36}"

and the resulting error message in Xorg0.log

[     3.071] (WW) NVIDIA(0): Unable to support custom viewPortOut 926 x 694 +49 +36

This problem has been reported in before here https://devtalk.nvidia.com/default/topic/540119/?comment=4129915

Any help would be appreciated!

nvidia-bug-report.log.gz (65.6 KB)

Internally filed Bug 200061674 to track this issue.

Thanks Sandip!