I've been having an oddball problem on one specific user account of my iMac (1st gen quad i7) that I'm hoping somebody else recognizes to save me isolating it the hard way. I've tried searching, but the only post at the Apple Discussions that I came up with had no replies. The symptoms are pretty straightforward: Some applications will hang repeatedly and routinely (generating a beachball and freezing any animation playing within), but as soon as you move the window (by dragging the title bar) or switch to another app (by clicking a background window), it immediately resumes normal operation, including registering any mouse clicks you made while it was hung. Additional notes: - Adobe applications seem particularly prone--Photoshop does this repeatedly while image editing, and any Flash video (Youtube, etc) will do it if you do any user interaction with the video (try to scrub, or even just mouseover to display the user controls). However, a video in QT Player X will also do the same thing, so it's not JUST Adobe apps. Interestingly, in QT Player 7, only the video hangs--the controls at the bottom of the window are still responsive (presumably they're being drawn by a different process). - It is ONLY on this one account--my wife's account, logged in simultaneously, is fine. My MBP, which has roughly the same software installed, is also ok. - I don't know exactly when it started, as I don't use this computer as regularly as my laptop, but it persisted through an upgrade from Flash 10.2 to 10.3, and at least a few Apple software installs. - It seems to temporarily go away after a reboot, but eventually comes back. - Happens even with no application but the one being tested open. - Repairing permissions doesn't help, and the disk checks out OK. - Activity Monitor shows nothing out of the ordinary, aside from showing the hung process as being, indeed, hung; CPU usage remains very low during hangs. - 10.6.7 with all updates installed, all 3rd party software up to date. Based on the behavior, I'm assuming it is in some way related to hardware graphics acceleration, since regular web browsing doesn't seem to have problems, or if it does they're drastically less frequent. The system-level things I have installed are CS5 (and its updater), SMARTReporter, the Canon wireless scanning utility, Logitech's latest LCC mouse driver, and Growl. All are also installed on my laptop, and none appear to be hanging in Activity Monitor. Any guesses at what it is that's causing the problem? Suggestions of things to try other than going through every process owned by my user by hand and trying to find a culprit?