All I can say here that it could be 4 things.
1. Is the Drivers? Are they up to date?
2. Did you install the Graphics Card correctly?
3. Your power Supply might not be enough for the OC
4. Try underclocking your card and trying again?
5. Is the Temperature of the GPU really hot?
Drivers are up to date, I also tried with old drivers
I'm pretty sure the graphics card is securely connected to the mobo.
I did try without OC and got the same results my power supply is PC power and cooling 750W
Temps or GPU and CPU are both under 60C