First of all, great thanks for releasing winSPMBT. I've been waiting it for a grand long time!
But there seems to be a major bug in the stacking function. If I select a unit and shift-click at a hex, any hex, the game will either crash to desktop with an error message or an "AVI Chunk Viewer" screen will pop up. For the record I'm using Windows XP SP2. I didn't have this problem with the DOS based SPMBT, nor with the other Windows based SP games.