Ever since the launch of WotLK, I've been having hard crashes. They seem to RARELY occur in some zones. Zul'Drak was the last lvling zone I was in where I crashed. It happens very frequently in Dalaran, though. Every time I come into or fly out of Dalaran via flight path I crash, and even while inside Dalaran it's only a matter of time before I crash.
Edit: Actually it happens constantly when I'm flying through different zones. Except instead of M2Shared.cpp as the file, it's MapMem.cpp
This is the error it keeps giving me:
http://i.imgur.com/tO5n37c.png
I am using the updated model WotLK download if that makes a difference.

