I don't think it's the maps. The few times in the last week that I was there for a crash, we were going to normal maps like Jurassic park or Roy the ship.
And the one night it was repeatedly crashing on the default map. It stopped after about 15 minutes and went on without problems for the rest of my time on.
I blame Valve.
The whole problem with the world is that fools and fanatics are always so certain of themselves, but wiser people so full of doubts.