New
#31
I had a similar problem with my new build. I have an i5-750 with an HD 5058.
After a fresh instaill of W7 x64 I installed Fire Fox then AVG then Zone Alarm. Then I started chain crashing with the grey/green verticle lines, similar to a lot of people with 5850's.
As soon as I uninstalled Zone Alarm my system became stable again and I haven't crashed since. So I would say it is a conflict with other software/drivers you have installed.
I'd suggest a fresh install and testing your system for stability after each progam is installed. Hopefully! then it will be as simple for you to fix as it was for me.