I'm getting this as well. In addition, my mailboxes aren't accessible, although my display indicates I've received new mail and I hear the audibles tones generated when I get new messages. When I attempt to connect in Desktop Manager I get connection errors and can't make any backups, syncs or modifications. I haven't installed any new apps in over two weeks, so this one has me stumped. I'll have to see what I can find.
Jakeyhead, did you ever did you ever manage to sort this one out?