video_set / minimize game, open task manager -> game crashes

Hi I have a problem with the screen resolution in my game.

My standard Monitor resolution is 1280 x 960.
If I set video_set(1280,960,0,1); everything if fine.

But I need to support more screen resolutions. My monitor also supports 1024 x 768 or 1600 x 1200.
If I set video_set(1024,768,0,1); or video_set(1600,1200,0,1); then one big problem happens: If I run the game and open the task manager, the game minimized and crashes! But why it crashes??
The game works with these resolutions, just if I open the task manager it crashes! Thats my problem. I hope someone can help me...

just checked it by running a project from SED in full screen, and it does not crash exactly but shows a black screen after starting task manager, and never comes back to work properly, so a forced shutdown is needed... seems to be another bad engine behaviour, similarly to notebook closing-opening resulting in making a fullscreen game windowed, that cannot be fixed without game restart.
I used 1920x1080 desktop, 1366x768 game resolutions.