This is a problem specific to windows systems when the parent window is maximized.
It can't be prevented but the effect can be minimized.
Use a script like this:
If [ Abs ( Get ( SystemPlatform ) ) = 2 /* this is a windows platform */ ]
Move Resize window [Name: get (filename) ; Current file ; height: Get ( ScreenHeight) ; width: Get ( ScreenWidth ) ; Top: 0 ; Left: 0]
Then, when you close the window, you need to use:
Adjust Window [maximize]
to return your system back to having maximized windows.
The Known Bugs List database includes scripts that handle window resizing in this fashion.