I finally solved this today, and like Brimstin have had this problem for many months. Whenever I opened the Desktop/ScreenSaver prefs, I would get the idisk.mac.com error, in my case four times in a row.
None of Linc's suggestions worked for me, as good as they were (I know they worked for some other people). I did use his tip of moving the iPhoto Library aside to narrow the problem to that. What I tried included:
- deleting all ~/Library/Preferences that referenced desktop, screensaver, or iDisk
- repairing the iPhoto Library database
- rebuilding the iPhoto Library database
- searching for aliases in my iPhoto Library (there were none)
- selecting all photos and correcting the ones that had bad links (nothing I corrected would stick though)
What finally worked was when I did a search of my whole iPhoto Library like this:
grep -R idisk ~/Pictures/iPhoto\ Library
and it showed me (apart from a couple of Library.apdb references) four problematic files—the same number of errors I was getting in System Prefs.
The problem files appeared like:
Binary file /Users/USERNAME/Pictures/iPhoto Library/Database/Versions/2010/06/04/20100604-144233/5Vt4pO7xQASBHKmXUjRA3h/Master.apmaster
These are reference files:
$ file Master.apmaster
Master.apmaster: Apple binary property list
So I looked inside them:
$ less Master.apmaster
catalso works, unformatted, but for some reason
plutildoes not decode the fileAliasData).
There I saw the smoking guns — in part:
Apparently I had put something from my mounted iDisk into my iPhoto Library.
I opened iPhoto, found these files, deleted them, and my problems went away. Hope this helps!
As a side note, particularly for those readers that are as not tech-savvy, all of these files were flagged when I did Linc's trick of selecting all photos, starting to move them, and getting the "original file not found" error. If you don't care about keeping all these files with lost originals, you can identify them this way more easily.
That didn't work for me because I couldn't tell which of the 10 files flagged were the 4 iDisk ones and didn't want to delete all of them. Also, I tried reconnecting which should have worked including for the iDisk ones, but for some reason they wouldn't relink to the local versions of the files I found.
Thanks! The grep helped me to pinpoint the elusive broken links and repair them. It should be noted that a problematic iPhoto library affects more than just iPhoto. I couldn't open iMovie without getting these error messages nor could I even change my system user photo. Now I can try to regain previous levels of sanity :-)