Hi folks - it's been exactly one week today with my refurb (from Apple online) 24" iMac 4GB/640GB stock config. I worked hard over the past week to get all my pictures imported from Picasa library (about 45gb), my iTunes imported in (about 60gb), some family videos (about 20gb) and ~420 contacts imported in AddressBook (thru vcards imports).. Got my desktop customized, users configured and all. Most importantly (as you will see below), got my TimeMachine running on a Maxtor 750GB ext harddrive. I have been loving the ability to play a slideshow quickly thru iPhoto, with my favorite songs from my iTunes library. Yesterday while playing a slideshow, I discovered that I can play/pause the show using the play/pause button on the keyboard. How convinient, I thought, and how well thought off by Apple. So I played with it a few times (play/paused). That's when the computer went hei wire . The slide show started playing multiple music tracks, and I felt like I lost control. I could not stop the show, I could not bring any other app to the front, I could not get to ActivityMonitor to kill the app/process. After struggling for about 15 minutes (when iPhoto kept playing the slide show with multiple music tracks), I figured I can use F3/F4 key to bring out Expose, and switched around enough times so I went back to iPhoto (until this time, I wasn't able to do command + tab to switch to anything else). As soon as I was able to go to iPhoto, I did command + q to quit, and things were back to normal (or so I thought). Then, I found that my AddressBook was gone from the dock (and was replaced by a "?") . Looked into finder, and saw that Addressbook.app wasn't even listed there! Gone .. poof!. Finder, Google desktop or spotlight couldn't find AddressBook (it found a folder in my personal folders, where I believe Addressbook keeps the imported vcard data). Then, I turned to TimeMachine for help. Located the application, and in about 30 seconds, restored it back to my Apps folder. Confirmed that my Apps folder had the same number of entries as in the last good backup, hence confirming no other app got whacked! Now, I am back to normal , system functional as normal. Don't know what happened. I wonder if I should worry about any other data integrity checks? Just not as familiar with a Mac to know what all I should check. Any ideas?