Vista - Microsoft Update taskbar icon not showing

I asked about this a few months ago but didn't receive any replies so
I'm trying again....

I have the system set to notify me when new updates are available but
the taskbar icon to show that updates are available never shows up for
me when logged in as a standard user. The icon is not set to "hide" in
Properties. I have to manually open Windows Update to see if there are
any new updates.

If I log in as Administrator the icon shows up correctly when new
updates are available. Is there any setting I can change to correct
this behavior?

--
Walter.