My friend and I still get desyncs when attempting to play 2v2 against the AI. Before we received desyncs at the beginning of the RTS battles, now they seem to occur during the middle of said battles. His thread is here:

http://www.larian.com/forums/ubbthreads.php?ubb=showflat&Number=468771#Post468771

It should be noted, as he states in his thread, that we can play skirmish fine, and the strategic part of of the multiplayer campaign mode fine. But RTS battles within the multiplayer campaign mode have always desynced. We both submitted our reports, hopefully that will help you solve this issue.