I have been having trouble with Ubuntu on my Dell XPS 8300 (Actual image of the desktop). I have heard that the AMD Radeon HD 6450 has trouble with Ubuntu, and I believe that it is the source of the problem (though I am no expert by any means).

When I boot the computer and choose to run Ubuntu, on a rare occasion both monitors (I have an AOC and a Samsung) will display their correct desktops, however most of the time, one of the desktops will be shifted away from its proper position and awkwardly positioned on the screen (showing the login box in the middle/right etc).

If anyone has any advice on how to fix this, that would be greatly appreciated.