Stop files in taskbar from going to thumbnails on desktop

Hello, I am new to Vista 64, Enterprise. I have turned off the flip 3D, but I still will get the items that are in the task bar to suddenly decide that I have forgotten about them. They will stop me from what I was working on by jumping up on the desktop in thumbnails. I will click on the one I want and it will come back as before. Example: I fly MS Flight Simulator. I also have TrackerIR4 and Voice Buddy minimized in the task bar working in the background. I am flying and for no particular reason one of them will pop up and stop the game until I minimize it again. Please, how do I stop this. I want to be the only one making the decision to un-minimize an item in the task bar by clicking on it. I have searched and been unable to find an answer to my problem.

Thanks,

Lynn Fisher