I managed to finally resolve a texture issue yesterday, but soon after I started playing, I was met with this. It's not a constant problem, and in fact, it's very sporadic. It can happen after a few minutes, or after 2 hours. I can just restart the game and continue from where I left off, but it is rather troublesome.
I'm using 32-bit Vista laptop, have a ATI Mobility Radeon HD 3400 Series video card, and am using the 11.2 Catalyst drivers, as a result of the texture problem mentioned earlier. I have already tried uninstalling and re-installing the 11.2 drivers to just to see if there was a bad install, but the problem persisted.
Hrm.... I'll see if I can hypothesize anything. I just found a way to trigger this reliably on a desktop with a Radeon card, but with large amounts of graphics card overclock (only in SK for some reason). I'm pretty sure you aren't doing this, but perhaps we could be tripping the same hang in the driver.