Screen flickering at high resolution

[neozengar]

I really need help with my graphic card problem. When I run at 1920 x 1080, there were occational horizontal lines on the screen. At 1680 x 1050, there is no problem. Can could there be something wrong with the graphic card? Below is my PC configuaration:

INTEL i5
ASUS P7P55D
OCZ 4gb ram
XFX HD 5670 1GB 128-bit DDR3
CORSAIR CMPSU-400CX 400W
Monitor: HP2311x

I really appreciate your help.

 

[Maziar]

It's probably a defective GPU.
Try installing the latest drivers or if you can test it in another rig.If neither helped,then RMA it

 

[Resonance_eSD]

Might be heat issues. What are your temps?

 

[ansonjoy007]

its probably a defective gpu..though you should try another cable...

 

[neozengar]

Thank you for the suggestion, I will try to RMA it. When I was using my old 1680 x1050 monitor, none of this ever happen. Also, sometimes my computer from sleep or shut up. I am suspecting it's a driver's problem. Any help would be appreciated!