I had this problem and was able to solve it. Here is what I did...
First, start the terminal application. I don't know how to do this with Mac GUI tools. Sorry. If you can not follow this, maybe post more question on what you can not follow and either myself or someone else may be able to fill in the empty spaces. Its late and I'm tired so I may get a little sloppy with my directions.
There is a lot file in ~/Library/Logs/Sync called dotmacsync.log. Look at the end of it. You can do "tail ~/Library/Logs/Sync/dotmacsync.log" or you can look at it with vi. In my case, I had stuff like this:
2005-11-16 22:22:01 -0600|Error|.Mac Sync Configuration error encountered while getting new configuration: *** -[NSKeyedUnarchiver initForReadingWithData:]: incomprehensible archive (0x30, 0xa, 0x3c, 0x3f, 0x78, 0x6d, 0x6c, 0x20)
The key here is "incomprehensible archive" but there is no path telling you where the f#$% it is. So, here is what I did:
First do this from the terminal:
find . -type f -amin -5 2> /dev/null | sort -o /tmp/old
Now, go to Apple->System Preferences->.Mac->Sync and recreate the error. Exit System Preferences. Now redo the find command above but to a different file like:
find . -type f -amin -5 2> /dev/null | sort -o /tmp/new
Then do a diff and see what new files were accessed:
diff /tmp/old /tmp/new
Lines starting with > are new lines. Lines starting with < are old -- files that were accessed within the past 5 minutes the first time but not within the last 5 minutes the last time. The ones you care about are the ones that start with >. Look at those files and see if something looks like an archive (if you are seeing the same error that I did). In my case, I found files in ~/Library/Application Support/SyncServices/Local to be the trouble. What I did was just move the whole directory to my home for a while with:
mv ~/Library/Application\ Support/SyncServices/Local ~
Then I logged out, logged back in, and retried the sync. If you try it without logging out, I guess things are cached up and it still gets confused.
Hope this helps
