Been happening for several builds. Finally getting around to reporting it.
I have quad display setup using two ATI video cards hosting two displays each.
Display 1 has the windows task bar at the bottom sized at double-height.
When I'm tagging, I have MC in split view using 2 column views and that is stretched across 2 display panels.
I assume that the program should remember it's window size and position when it is closed, and then reopen exactly as it was last time.
What happens is I stretch MC across the 2 display panels. It is in windowed mode, and not maximized.
Using the X button in the upper right corner, I close the program.
Open the program a bit later and initially it re-appears stretched across the 2 displays just as it was.
This is perfect! ....but wait.
A few seconds later, the program resizes itself to only display 1. It also isn't respecting the double-height taskbar and is covering most of that. I have to resize MC to get to the start button.