You mean to say you're getting this on the GTX 590?
Sounds more like the RAM on the GPU is failing. Could be a failing PSU is causing the Voltage to either spike or drop leading to this.
Check them both on other rigs and see if it causes the same problem.
No, this is on a Radeon HD 4870, about 2 or 3 years old.
I returned my GTX 590 that I bought today, swapping it for a HD 7970 (hasn't arrived yet), but that is besides the point.
I think it may be the video card, because I am using onboard graphics right now and everything is running perfectly fine.