Possible Fix for "forbidden" 403 error on iPhone
 

My OF is working fine for both desktop and iPhone, but we set it up on my wife's computer and iPhone (yes we bought multiple desktop licenses :), and told the phone to get the settings from her MacBook. We had the MacBook sync it's information to her .Mac in Documents (default setting).

Then we setup her iPhone, the .Mac settings carried over and almost immediately we received the "forbidden" 403 error on the phone, but no issues or errors with the desktop. I reset the database on the iPhone a number of times but no fix.

After looking through the forums and not finding much about iPhone errors like this, I figured I'd try to do this via the webdav settings and type everything in manually. So I popped over to the WebDav settings and typed in the web address, but replaced it with the me.com domain and path to Documents instead of using the .Mac domain. The first sync failed with a 501 error (might be wrong about that number), the second attempt asked for a password, and login, after entering them it connected fine.

The only issue we've had is that upon the third sync we had to replace the local copy of the database on the iPhone with the server copy, due to an error with syncing. It's only happened once, but other than that, it seems to be working fine.

I wonder if this is an issue with the new changes in the MobileMe service from .Mac. I setup my phone and desktop before MobileMe was released and haven't had any issues whatsoever, it's been working great, even after the transition. Anyway just an FYI for everyone.