At some point, the items in the KDE taskbar will no longer update. 
How do I fix this?

Some background: I've been running Mandrake Linux 10.0 on my personal
machine since last June (about a year).  For a few months now, but not
before then, the taskbar has been having these problems.  I generally
run Linux for long periods of time (uptime 8 days right now, as much
as 3 months in the past) and stay logged into KDE as one user this
entire time.

For example, if I am running openoffice and mozilla before this
occurs, and then I close mozilla and open kcalc, I will still see
openoffice and mozilla in the taskbar, and not kcalc.  I can click on
openoffice and it will be brought to the front, but clicking on
mozilla does nothing (since mozilla is closed).

Alt-Tabing still works, and I can see all the correct apps in the
alt-tab popup menu.  Also, if I right click on the taskbar and select
configure panel, then make some change to the taskbar settings and hit
ok or apply, the taskbar will restart and will work fine (for awhile).

I have not noticed any pattern in the times at which this error
occurs, but it happens a few times a day.