I had a problem. When I tried to Sync with my .Mac account, it would give me an error message. I found a log file in ~/Library/Logs/Sync called dotmacsync.log that said that some archive was corrupted, but it did not give me a path. So I waited for a while and then did this (from the Terminal) from my home directory:
$ find . ! -type d -amin -1 -print 2> /dev/null > /tmp/F
/tmp/F will be empty if the machine has been idle for a while. Now I went through the process to produce the error message and redid the command. The command finds all files which are not directories which have been accessed within the past minute. After the second find, /tmp/F had about five files in it. A few were plist files that seemed to be trashed. I created a folder called ~/OLD and moved all the files listed in /tmp/F there. They were pref files and a few files used for sync. I didn't know which one was bad, so I just moved all of them.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20051001164608750