I have the same card as the OP (ATI Radeon HD 4200 mobility), and I have the driver package from the ATI website. I am not really sure what I need to do however. My laptop is secluded from the internet due to BT4 Final R1 not seeing any interfaces, so I had to download from a windows computer and put it on a flash drive. It is in a .run file. How do I go about installing that from a flash drive without being in KDE? Sorry for lame questions, I am a linux noob with like 1 week of experience inside Ubuntu 10.04.
EDIT: I kinda answered my own question. I put the .run into my home folder, and managed to find it with a dir.