Not and end of the world situation just annoying so I thought I'd post something so they knew about it. Before I figured out what was causing it I'd get very frustrated because it seemed like all my tools would no longer work (when in reality they just weren't working outside the selection area). Whenever I select something with the marquee tool, then either move it or transform it the selection border disappears. The selection is still active. I have to press ctrl-d to deselect before going back to working, although there is no visual cue that i must do so anymore. I can replicate consistently as it happens every time I follow these steps.