I am running 10.4.8 on an iMac G5. Recently most of my iLife applications stopped launching. When I click on the icon in the dock I get one "bounce" and then nothing happens. When I double-click the application icon, nothing happens. The affected applications include: iChat iCal iDVD iPhoto iTunes Safari Mail Address Book Other applications such as MS Office, Firefox, Backup, Appleworks, Photoshop, etc. work fine. When I boot the computer from my external drive which is also running 10.4.8, everything works fine. So far I've run Tech Tools Deluxe and Disk Utility. Tech Tools found some volume structure problems and appeared to repair them fine. I've also deleted all of the cache files but still no luck. Something that affects the Apple applications must be corrupted, but I don't know what else to try. Help!!!! Thanks.