Do you have the latest patches? I see a lot of people mention their game crashing, and I have the problem every now and then myself. The majority of the time though my game only crashes after playing a long time or because I tend to play on huge maps on marathon speed and there seem to be some memory issues associated with BTS. Granted I'm playing on version 24 rather than the Age of Ice mod, but I would think any problems for one would also be present in the other.
I definitely recommend patch 3.03 followed by Solver's unofficial patch. That's how my game is patched and like I said, I don't get a lot of crashes and when I do I think it's memory related, and I'm using 2 GB of DDR2.
On that subject, do you have enough memory?