http://bugs.winehq.org/show_bug.cgi?id=34041
--- Comment #10 from zoroaster zoroaster@inode.at 2013-09-16 16:53:11 CDT --- (In reply to comment #9)
Does Activity Monitor show network traffic while Steam is trying to shut down?
No, not really. Most of the time after stopping Skyrim I had about 30 bytes per sec (with peeks of about 300 bytes per sec).
If you configure Steam to not sync to the cloud, does it exit promptly?
Steam is already configured to not sync to the cloud. When stopping the Steam task it shuts down without any problem except while the Wine process of the game itself hangs. Then you get an error message from Steam that says you must first close Skyrim and you can shutdown Steam normally in that case again after you kill the hanging Wine process of Skyrim.