I've searched through the postings here, but I haven't found anyone else with a similar problem. I'm really stumped. I've blogged about the problem on my BF's Mac blog in these two posts: http://www.gaywithamac.com/2007/10/boyfriends-experience.html http://www.gaywithamac.com/2007/10/argh.html In a nutshell, I installed Leopard on my iMac (latest gen 24" with 3Gb RAM and the faster processor). After Time Machine runs for a few hours, I am not able to start many applications. In particular, I've noticed that I can't open Preferences, or iTunes, or Front Row. (The apps will show as open, but they aren't really open. In the dock they show the "force quit" option, but if I select force quit nothing happens. Hitting the key combo for force quit does not bring anything up). However, Safari and Firefox open and run fine. If I eject the Time Machine external drive and stop Time Machine from running, suddenly the applications that I tried running previously open up. So Time Machine is somehow keeping these applications from opening. I'm really stumped, and don't know what to do next. (For now I'm keeping Time Machine off until I can get this figured out, but I would really like to get this working!) Thnx in advance for any help you can provide.