Screen black for 1 -2 seconds when opening VLC or Youtube

Hi,
since tomorrow I’m experiencing the following problem: when i open VLC or Youtube, the whole screen become black for 1 or 2 seconds, as if i turned it off (but I didn’t) and i can still listen sounds and type in the keyboard (oS is not hanging).

Hardware info:
CPU: Intel Core i5 750 at 2.66 Ghz
RAM: 8 GB
Video Card: AMD Radeon HD5830 with 1 GB of VRAM.

Do you have any idea about how to solve this problem?

Thanks in advance,

Bye
hawake

Possible workaround: configure VLC with a different rendering engine.

To fix this I reinstalled Radeon drivers and the bug got fixed.

Bye
hawake