I upgraded my Ubuntu 8.10 to 9.04, and it not only broke the ATI proprietary fglrx driver, but also the ability to use the VESA or open-source ati or radeon drivers.
I have an ATI RV610 which is an ATI Radeon HD 2400 XT.
I have Linux Kernel 2.6.27-14-generic and 2.6.28-13-generic.
With fglrx, vesa, ati and radeon, the Xserver hangs the machine as soon as it starts by invoking X or startx, which is seen by observing that caps lock doesn't work. There's nothing useful in /var/log/Xorg.0.log, no errors at all. This is with either kernel.
When I download a new proprietary driver from ATI, I install it successfully on kernel 2.6.27, and it doesn't hang when X starts up, but it just shows a blank screen and does nothing. I also can't CTRL+ALT+Backspace out of X at this point.
In all the years I've used ATI's Linux drivers, this has happened almost every time I've upgraded my kernel, but it's been fixable with much effort. This time I'm really stuck.
Does anyone know how to fix these problems?