my u2412m after 1 year - Entering Power Save Mode for VGA Cable

Hi, Hi, i bought u2412m 1 year ago and I use monitor for my two notebook (fujitsu siemens amilo pa2548 - DVI, Vista; acer 5820TG - VGA, win 7 64). All worked ok. But last week, I played settlers 3 on acer and after than, entering power save mode EVERYTIME, when I want to use VGA cabel (DVI still works). I checked some topic on forum, reinstall driver for graphic card, search monitor driver (site doesn't work), try some tips, but still nothing helps me. I write this topic as another opportunity to solve my problem. Thanks for response Jakub