I have a similar problem with my ati card. After I upgraded to 10.10, I installed the proprietary driver and all I get is a blank screen. Not cool. So, instead I used the default driver loaded from the kernel. Works fine but can't take full advantage of 3d-rendering.
I also have another that will only take ubuntu 9.1. Any newer distro will not work it...newer ubuntu system. Apparently, the default driver is not accepted, don't even have the option to install the propriety driver.
I'll take a guess and say that with each upgrade of the kernel module are re-written or patched. What ever was patched in the kernel related to the video driver will not work with yours or my system. And, modules are not loaded until the kernel is loaded after booting.
Take a look at the kernel ubuntu 9.1 is using and see if you can find other distros that use the same one or, run "lspci -v" and find your vga controller section and note the driver and modules that your kernel has loaded for your video controller. Then take that information and check all kernels to see if they are using the same ones. Bit of work but will help out in the long run.
Look at this site for a listing of all recent kernels and view their change logs.