Very strange that was, and the only time it's done anything like that. Had no problem in games when it's been using the grpahics card, only when it's been sitting on the desktop but could be the graphiocsa card.
Can the i5 be used with a single stick of RAM? I could try that first, swapping between the two and then replace the graphics card with my old ATI one which I assume woyuld just work with the current AMD drivers installed.