Inactive Icons in Notification Area Won't Hide

[Lyle]

I seem to have lost the ability to hide inactive icons in
the notification area of the task bar. I have right
clicked on the properties section of the task bar and
checked the hide inactive icons box, but the icons will
not hide, and the the little chevrons (<<) that used to
appear when this function was operative do not show. I
can display or not display the clock, but unfortuately
checking and unchecking the hide inactive icons box has
no effect.

The problem started after I loaded the most recent
windows update. I tried system restore, but there was no
change.

Any help would be appreciated.