I've spoken with Apple since the first day OS X Mavericks was released. I installed it on the first day it was released. Everything is fine but one thing. I keep getting QTKitServer not responding in Activity monitor. Something keeps breaking. Like I said, I've spoken with a Senior Advisor for Apple about this issue. We have done three or four things to make this problem disappear. I just don't know what to do now. I even reinstalled OS X Mavericks, and I am on a fairly new Macbook Pro. Well, I mean, it's a late 2011 17" Macbook Pro with 16GB of Crucial memory and a 250GB SSD inside of it. There's plenty of horsepower to run Mavericks, and I have plenty of free RAM all the time in Activity monitor. Anyway, has anyone else been having QTKitServer turn RED in Activity monitor after installing Mavericks and running Safari for awhile? On a humorous note, the last QTKitServer that ended up not responding in Mavericks was pretty evil. Check it out! It's the mark of the beast: "QTKitServer-(666) Safari Web Content (668)" not responding. If anyone has any suggestions how to perform an exorcism on my Macbook Pro, please let me know in this thread. Thanks!