BenDansie

I have an issue with SM4deluxe. I will be playing, then needing to go to the desktop. After finishing what I am doing, and going back to the game, I find that there are now black squares in various places on the screen. with this I also cannot use the mouse to do anything. I am running Windows 7 x64 laptop with a Nvidia card inbuilt. any helpw ould be appriciated. Thanks Ben