Comment 8 for bug 321613

Robert,
I was going to ask why the 9100M G would be the only C77 card to be supported. In bug 333040, Asif Youssuff provided a clean set of log files that demonstrates how the GPU fails under karmic. https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nv/+bug/333040/comments/27.
What I found troubling is that the "nv" driver get loaded even in the absence of the id in the nv.ids file.

(==) Matched nv for the autoconfigured driver
(==) Assigned the driver to the xf86ConfigLayout
(II) LoadModule: "nv"

This would explain the line later in the log:
(WW) NV: Ignoring unsupported device 0x10de0844 (C77 [GeForce 9100M G]) at 02@00:00:0
(EE) No devices detected.

The expected behaviour when the id is not supported is to load the vesa driver. I suspect that when the id is manually added, the vesa driver is loaded (an equally incorrect behavior) which leads to claims that it now works. We have yet to see hard evidence that the "nv" driver is loaded and performing adequately. I am only speculating, but one difference between IGPs and discrete video cards is that they have support in the kernel for the chipset.

I know this is a side issue, but it may lead to the resolution of this bug report. Further more, the main design point of a vesa fallback driver was to avoid a "crashing video" scenario to provide a great "out-of-the-box" experience. It does not seem to work in the case of the 9100M G and I suspect it does not in the case of other IGPs.