this is not an emergency more of a curiosity. 

every so often i will be creating a sketch and completely lose the ability to edit sketch dimensions.  I draw a line the dim is automatically set to add itself and open the edit window.  except the window does not open and a double click on the dim does not open the window either.  it acts like a driven dim but its the only line in the sketch.  once this occurs NO dimensions can be editted AT ALL until SW is reloaded.  I can save files and when i open them after restart the problem is gone and everything is where its supposed to be.  i cannot recreate this behavior and it is extremely rare, im just curious to see if it happens to anyone else.

thanks for indulging me