AnArKiSt wrote:Sorry about the really late reply.
My graphics hardware is called "ATI Radeon Xpress 1270"
In my experience this happens when the graphics context is destroyed by the OS for some reason - typically to do with video driver being reset for some reason or another, usually a form of driver crash (which may or may not be related to overheating).
A typical case is a graphics card overheating and then the driver is reset (causing the screen to go black for an instant and then windows reappearing one by one) by the Vista/Windows 7 kernel to keep the system usable
In your case I do not know what is going on, but the symptoms are consistent with my own experiences with Vista video driver crashes and the kernel recovering from it.
One weird workaround you can try (and I've had this work!) is this one:
Click the still-running game on the taskbar, no window pops up.
Blindly type: `vid_restart<enter>
If it fails, try a few times until it is typed correctly, when you get it right it tends to spring to life in a new window exactly where you were.