Recently, my mid 2009 Macbook Pro & my Late 2010 iMac have all been acting up. Both are running Mavericks. For example on my iMac, when I run Motion 5, after a few effects and layers the whole thing crashes, and I loose my work. But apple is silly enough not to put in an auto-save / recovery system to keep my work. Now recently, I decided to try iMovie '13 and it did this to my iMac: Wow. Couldn't believe Apple was capable of doing this. After this happened I rebooted my machine and it was gone. But this tells me that my GPU could be failing. Now I load iMovie '13 onto my Macbook Pro. The whole thing locks up a few times and then the thing that really made me mad happened, it rebooted my entire machine with a "kernel" error message. Ok, just great. Oh, and another thing I hate about my iMac at the moment is that the Superdrive only lasted till last year. Again, WTF? You spend premium on this hardware and you would expect it to last a long time. Apple, really get your act together. Stop messing things up.