I had a complete computer meltdown last week and have been battling persistent demons even since starting over in a new user account. So I don't know what the problem is, but when I tried to upgrade my Canon software to the newly released versions, it wouldn't work. I got an error message that it could not do the upgrade. So I tried dumping everything (from Applications, Library/Preferences, and Library/Application Support) that said Canon, DPP, or EOS in the title. And then I rebooted from a Leopard system CD and repaired my permissions. It fixed a list of items. Then I clicked Repair Disk, and it didn't find anything to repair. So then tried to reinstall the previous versions of DPP and EOS Utility from the Canon CD, and it couldn't install them. It keeps returning an "error = 6" message. Help!