Thanks very much for the reply. I went ahead and flushed all of the local game content and re-downloaded it from Steam. I wanted to avoid the download but based on your advice I went for it.
It now appears to work just fine! I can create a new game and also connect to a multiplayer game without incident.
And thanks for the tip on how to sample system/application activity during force quit. Interesting feature!
Love the game -- look forward to what you have in store next!
-Nixx