I recently found some screen problems with my 2009 MBP. After it was repaired in an authorized service provider (screen changed from a LG one to a Samsung one), everthing seems to be fine. But, then some other problem just appears: whenver I move a window to the left/right side of the screen in a position near the dock, the dock will have a uneven/blurry white side line. Of course it may be more obvious because I use a black dock skin. But even with the original transparent dock, you can still see this line. Tried resetting PRAM, restarting for several times, no luck. Anyone knows how to solve this please? I'd rather not to send it for repair again after just getting it back from there.