Finally...Someone who has my exact same problem.
Delta, since the games alpha release I've been getting the exact same issues as you. I also have a 2011 based i7 CPU and a ATI7970. I'm not sure if it helps but I'm also running an Asus Rampage IV Extreme.
I also get the Black screen or white screen lockup where I can only assume the VGA has locked up. Guys, you can't old tab out of it. You can't do anything but I can tell you that the whole system hasn't locked up because at one stage I was on skype with a friend while playing and it locked up and we were able to finish of our conversation. Since then I have done a few things. I have formatted my computer 4 times. Each time removing a little hardware. I've got the system down to 8gig of RAM, the 7970 and my systems hard drives. I've gone through all the graphic driver versions and nothing helps. I went to the dev build and it was more reliable but still crashed eventually and like Delta, if you lower the graphic settings the game seems to be much more stable but I have tried this recently as I've been formatting my computer constantly hoping that it was some strange piece of software that I have installed or too much RAM or some such.
I hope we can bring attention to this issue more than anything. For weeks I have thought I was the only one.