I can't seem to launch a co-op quest. I form a party and launch the co-op quest, but after a few seconds it doesn't load and gives an error "Launching game host failed . Then it says "Games for Windows - LIVE Connection Failed: (User1) could not connect to (User2)." User1 and User2 are the actual user names.
Another time I tried running it with someone else and I got an error that the games were out of sync and my AOEO client crashed.