Stopping debugger when run has stopped.

When you debug a program and it finished cleanly, the user still needs to stop the debugging process by clicking on "Stop" in the debugging window or pressing Ctrl-Shift-F7. If they don't do this subsequent attempts to debug the program won't work.

Could you not simply automatically stop the debugger when the call stack is empty (and the big red square with stopped appears in the debugger panel)? Forgive me if this is a silly suggestion but I have not grasped the technical reason for leaving the debugger running.