ATI HD6670 weird issue

Hey guys

I am experiencing a weird problem with my ATI HD6670 graphic card.
There is a horizontal line ( fracture ) during watching videos or movies, or scrolling up or down a website in a web borwser.
I tried to do a screenshot and even a video but when I play back it is not visible.
Only when I use the browser or watching the videos.
I would describe it as a flimsy or thin diaphanous fraction on the screen.
It is "running" through the screen during watching movies, videos.

I have updated my catalyst, and nothing changed  
It can not be the monitor cause same issue if I used it on a tv with a hdmi cable.


Has anyone got an idea what could be   ??