Other than the
Cannot Battle... topic you alluded to, a few other people reported this problem in the topic
Crashes on skirmish, one mentioning it had only started since the last beta update.
Are you shutting down all non-essential programs before starting the game? The anti-virus program may have been the issue in the first topic.
Have you tried lowering the resolution, or changing it to match the desktop resolution if it isn't already? Did you lower / change the graphics options?
Did you check for Windows updates, graphics drivers, etc?
