I bought an ATI Radeon HD 4870 from Apple's website about 6 months ago. Well, last month, it stopped working correctly while I was in Windows playing a game. Pixelated artifacts started showing up all through my game and when I booted back into OS X, the pixels were even showing up in quicktime movies (attached is a screenshot). Anyways, I called Apple to have them replace my card since the card came with a 1 year warranty. However, as I was talking to the gentleman on the phone, he explained to me that my serial number was showing that I had an unsupported machine. Basically, since my machine is a first gen 2006 Mac Pro, he couldn't get me a new card because Apple's website specifically states that it works with 2008-2009 models only. He actually tried to replace it for me anyways, but the system wouldn't allow it with my serial number. It pissed me off that the defective card cannot be replaced or repaired because I'm using it in a Mac Pro that it clearly works with (I used it without issues for 6 months and many people are still using theirs today). Edit: I called my local Mac repair/reseller "MacEdge" in Portsmouth NH, and explained my whole story. I told them that I had an unsupported machine and that Apple would not allow me to return the card. Well, they tried anyway and they even used the same serial number I used on the phone before and Apple accepted it and they're sending a replacement for me! It should be here at the beginning of next week. Sweet! In case you're curious, I changed the thread title and topic because the rest of the conversation in the thread is basically about this specific issue and not about what I originally posted. The thread quickly turned into a discussion about this, so I figured I'd change the title and first post to reflect that. I also wanted to let everyone know that I got lucky and MacEdge took care of it for me. Thanks for all that read my story and I hope some of you too get as lucky (in case your ATI 4870 breaks). Anyways, here's the screenshot I promised. Happy New Year! PS: About the screenshot, notice the weird pixels in John Cusack's face. The weird thing is, even if I pause the video, the pixels stay right where they are and do not change even if I move the window. They stay right inside the movie file. This happens to all of my videos regardless of encoding and I even get some off colored pixels in my menu bar and some icons.