I found this on ProLost…
“Apparently the new DRM-checking routine will stop your After Effects render after ten minutes because it thinks you’re trying to hack your own file. And since Adobe finds out about Quicktime updates the same day you and I do, here we are.”
This is what happens when Apple updates Quicktime to enable features in iTunes or for the iPhone…and doesn’t give beta builds to companies that rely on QT as part of it’s core rendering component. QT 7.3 broke a few things, QT 7.4 broke a few more. All so you can rent a movie that you can get CHEAPER if you subscribe to NetFlix.
EDIT: And a thread over on the Apple boards.