A mintUpdate padlock is missing from the taskbar of a Mint 6 installation. The user doesn't know what caused the disappearance but thought it was when an update took place. I haven't personal access and have to talk the user through by telephone, but I have verified the following:
The taskbar notification area still contains the Loudspeaker, Date/Time, and Network icons.
In Control centre > Sessions > Startup Programs tab, the mintUpdate application is ticked.
Updating can still be effected through Control centre > mintUpdate.
I've looked up past questions which mentioned adding Notification Area by using the Add to Panel facility, but in this case that didn't seem relevant because other icons are still being displayed.
So, how to get the mintUpdate icon back on the taskbar? Please!