I wasn't sure if I should post here or in the hardware forms, but here it is. I'm running ubuntu 12.04 64 bit, and I have a radeon HD 5550. I want to use my GPU for things like pyrit (GPU accelerated hashing/cracking), so I tried to install the ati propriety drivers, it all goes well, until reboot. all I'm presented with a purple (and only purple) screen (well two). I had no idea, where to go from here. Any help is appreciated.