It looks like a false alarm.
I use Standby and Hibernate all the time and only shut down perhaps every 2-3 days.
Somehow the desktop Chrome icon function must have got paralysed during the sleep period, because when I eventually did shut the computer down and restarted it, the Chrome icon is now working.
Sorry for the false alarm, but the icon freeze puzzled me. Just re-booting never entered my mind as a solution.
Edited by Skippyroo, 18 October 2013 - 07:34 AM.