I bought a new computer with a GA-A75M-UD2H motherboard. I installed Windows 7 on it with no problems but was wanting to install Kubuntu 11.10 or Linux Mint 12. Whenever I try to install from a live CD, I select what I wish to do, hit enter and shortly thereafter the screen reports that there is no signal. The DVD is still working but I have no video. If I remove "quiet" and "splash" I get the following:
RADEON(0): Chipset: "SUMO" (ChipID=0x964a) requires KMS
Screen(s) found, but none have a useable configuration.

Any help with this problem would be appreciated.

It appears that the Kubuntu/Mint Live discs are having issues determining the appropriate settings for your monitor. Please ensure that it is well connected to your computer. Another thing to try is another distribution as your computers hardware may be too new for Kubuntu 11.10.

I had initialy tried Linux Mint 12 with the same results. This morning, mulling over other comments re this problem, I decided to install the video card from the previous computer. Voila! It works. So it would appear that the Radeon A6-3650 chip is not supported. Any ideas when support might be added to the kernel?

Unfortunately not. Your best bet would be to follow Radeon development and keep trying successor distributions - or alternately boot the system with the VESA driver and then install the proprietary ATi driver.