I eliminated this problem as Jase says above in comment #6.
I was using the gnome "Shut Down" applet beside my notification area. I swapped this to the "Indicator Applet Session" and I have not seen the problem since. Those 2 applets give similar functionality.
Note maintainers, as I said above in comment #8. I was using exactly the same applets on my slower laptop but never saw the problem there. So I contend this is a timing/speed related problem.
I eliminated this problem as Jase says above in comment #6.
I was using the gnome "Shut Down" applet beside my notification area. I swapped this to the "Indicator Applet Session" and I have not seen the problem since. Those 2 applets give similar functionality.
Note maintainers, as I said above in comment #8. I was using exactly the same applets on my slower laptop but never saw the problem there. So I contend this is a timing/speed related problem.