Hi, I was wondering if anyone could help me. This morning, whilst reading through the GPU failure thread on the Early 2011 Pros (funnily enough), a horizontal line appeared on the lower half of my screen. The line is always there unless I take a screenshot where it is no longer visible . I have tried restarting the computer and have ran an extended Hardware test where no problems were found. Does anyone have any ideas as to what it could be? Although it isnt a huge problem, it does get slightly annoying after a while. The spec of my Mac is as follows: MacBook Pro (15 inch, Early 2011) 2.2 GHz Intel Core i7 4GB 1333 MHz DDR3 memory AMD Radeon HD 6750M 1024MB graphics Cheers.