I recently switched from Vista to Ubuntu 12.10 on my HP laptop and I've been having issues with my graphics. Everything is fine till I watch a video/play a game or (sometimes) when I visit the software centre. At that point large portions of the screen start flashing and everything gets rather slow. I'm looking for a way to remedy this. For reference I'm using Firefox and I'm unsure what my video card is because it's listed as unknown when I check my system settings.