Cheers, going to get it replaced on Friday when I have the time.
EDIT: Had it replaced today, first replacement was an LG screen, was going to walk out with it but decided to have a look at the demo models, the difference in image retention between the Samsung and LG screens was way too much (Photoshop, Illustrator and InDesign have grey backgrounds so the IR would show up every time I switched docs), so I replaced it again, luckily the third one has a Samsung screen and a keyboard that doesn't sound as if a bee was trapped in it. Happy with it now, shame about the lottery that you have to go through to get a perfect model though!