All windows move to second screen when playing a full-screen game

I have a dual-monitor setup with the second monitor extending the desktop (not mirroring the first). I like to play old games and I discovered an annoying bug when I switch the game on the first monitor to full-screen. Since the games are old, they typically use a low resolution of 640x480 or 800x600, below that of the native resolution (1440x900) of the primary monitor. All open windows obviously don't fit on the primary monitor at this low resolution and they move to the second monitor. When I finish my game and the primary monitor returns to the native resolution, all windows remain on the second monitor and I have to drag them back to the primary monitor. This is rather annoying, is there any way to automatically move all open applications to the primary monitor? Please help.

PS: I tried to temporarily disable the second monitor. All windows return to the primary monitor, but they go back to the second monitor when it is activated again! Is there any better workaround?