I have Ubuntu 12.04 LTS 64 bit and I have installed proprietary drivers for my Radeon HD 7670M with 2GB memory. But if I scroll page or do anything like move a window then I get blurred screen (more like scrambled maybe) for a second and if I try to take PrtScr of it, it is goes to normal.
I have tried other drivers and it does not solve my problem. And I do not want to go over 32 bit Ubuntu because I have 6 GB ram and I would lose so much of it. Also if it helps, my processor is Intel® Core™ i5-3210M CPU @ 2.50GHz × 4.