I've had problems with the waveform in Sound Studio breaking up when scrolling sideways as described in this thread. Here's a pic of the waveform breaking up if you can't be bothered to click on that link. I also have encountered other problems. In Mail the text breaks up above unread (bold font) messages when I scroll the messages list a certain way (not too fast and not too slow). Here's a pic with 3 screencaps of it. Then in Google Chrome if I resize a window with Flash video playing it produces some errors in the video. Doesn't happen on any other browser though and the errors are only momentary and limited to the Flash video. Here's a link to a screen recording I made of it. http://dl.dropbox.com/u/5417088/Screen%20Recording.mov The computer feels a bit sluggish every now and then and for example iPhoto can be a real pain in the ass as it might lag a lot and spin the beach ball. Exposé also is really jerky most times, especially if I haven't used it in a while. Might start to arrange the windows but then stop or just completely skip the animation. Then X-Moto is pretty much unplayable due to it's terrible sluggishness. For example the tracks Green Hill Zone Act 1, 2 and 3 are all absolutely impossible to play as they're so jerky. X-Moto worked fine on my old MacBook though. Today I decided to test how a more demanding game would work, so I installed Half Life 2 demo and it ran without problems. It would jerk a bit a few times per hour maybe, but overall it was very playable. So that was kind of a surprise to me. I have ran the Apple Hardware test from the OS X install disc and it didn't find anything. I've updated everything, repaired permissions using the install disc, reinstalled Snow Leopard on top of the current one, tested on two different hard drives (both 500 GB, 5400 rpm, the other one Hitachi and other one Western Digital), tested with all possible RAM configurations (changing the slots or testing with only the other RAM stick), reset PRAM and SMC and nothing has made any difference whatsoever. Then yesterday while I was checking out what Time Machine is up to, the window looked like this. I dragged it around and it didn't change, stayed the same and didn't produce any errors anywhere else on the screen, which I found a bit weird as from my experience that always happens when the GPU is shot and starts producing errors. So yeah, I really don't know what to think about this situation. Definitely something seems to be up with this computer but I cannot produce any real bad errors in any way and the computer has never crashed or anything and the Hardware Test doesn't find anything wrong with it, so if I take this to the Apple Service in town they might not find anything wrong with it as the computer works just fine after booting it up and the errors are rather minor and mostly not related to Apple software either. So what do you people think about this situation? What should I do? Is there any way of confirming that there is something wrong with the GPU or some other part of the system by myself or something I should try doing? Also if anyone with a similar MBP could try to reproduce some of the errors or test out for sluggishness in X-Moto for example (it's a fun game and completely free) or scrolling a waveform on Sound Studio (demo of Sound Studio 4 can be downloaded here) or give me just about any advice, I'd really appreciate it.