I've got almost nothing to lose at this point, but it wouldn't hurt to ask before investing yet more hours in something that won't work for me.
My current system:
Gigabyte MA-GM78-US2H motherboard, vintage 2009.
AMD 1090T CPU.
Ubuntu 11.10, 64-bit.
RAID1, administered by mdadm.
Video card was an NVidia 8800 GTS. I just upgraded to a GTX 460 card -- specifically, a Gigabyte GV-N460OC-1GI.
This system went down last month because of NVidia's recent driver bug fix, which was apparently meant to address a security problem and thus had to be patched to all driver revisions, new and old. Unfortunately, the bug fix wreaked havoc with systems using somewhat older GPU's, like my 8800 GTS.
I could still run the system without a driver, but graphics were hopelessly slow for my 3-D protein visualizations. I'm guessing that my CPU's were doing all the rendering, and the GPU's were just sitting there, inert. I also need CUDA.
After trying for a week to get my system going again, and seeing that NVidia was not addressing the problem (although, they might have finally done so, two days ago?), I thought I would try upgrading my GPU card. That didn't work. Now I can't boot from my hard disk at all, only from a LiveCD into a sub-optimal graphics mode. I've spent a second week trying to resolve that, with little success so far.
My son's system down the hall is running fine. It is ALMOST identical to my system, except that his motherboard is a bit newer (Gigabyte GA-990FXA-UD5), and his GPU card is a little older (GTX 450).
My /home directory is backed up to an external drive. So, technically, I can do anything I want from here. But I'm tired of trying things that do not work.
I would consider upgrading to 12.04, 64-bit, IF that would help me. This thread and this thread contain reports of some people fixing video problems by upgrading their OS -- and some people getting unsatisfactory results, sometimes even acquiring problems. At least, it would appear that most of the people having problems in 12.04 can actually boot their machines.
I thought it might be a good idea to ask the question directly, not buried in another thread. Did you fix your video problems by upgrading? What were the specifics?
Thanks for your testimonials.