I connect my laptop with a LCD display Samsung T240.
My laptop HP 8510p has ATI mobility 2600HD graphic card. Connection between both is established with HDMI. OS is WinVista 32, SP2.

The problem is my monitor often blinks (picture becomes black for a second, also sound is interupted). Before a blink some tiny lines are shown on the screen. Blinking is more often when running a 3D game, when draging a window over the screen more intensively, when click on 3D options in ATI Control Center (where some 3D graphic is shown)...

So, what have I done so far?
- I used two different HDMI cables, same result with both.
- I tried VGA cable, everything worked fine except one blue screen (display driver) occured.
- Primarily I have HP mobility driver installed. I deleted it and installed newer driver from ATI (amd) website with a modder support (because this graphic card officialy supports only HP edited driver). Same result. Then I uninstalled it and wait windows to recognize a graphic card and specify a driver for it. Still same result (blinking).
- On my friend's laptop everyhing is working just fine. He has a Nvidia card (8xxx something).

So, most likely problem is ATI driver. The question is, is there a solution or do I have to get rid of my Samsung T240?

Thanks for any replies.

Have you checked what refresh it's running at? And what refresh rates are supported by your monitor?

Supported refresh rates are 59Hz and 60Hz. I tried both of them.

Also I noticed that when my laptop is on battery blinking does not occur so often.