QUOTE(kps @ May 15 2003, 10:07 AM)
Have you tried Software Update? In some cases you need other updates (like security updates, etc) before some of these combo updates will work.
Launch the Software Update application and see what choises it gives you.
Combo updaters have ALL of the necessary updates...security ones included. That's why it's called combo 
From Apple's site that Al linked above:
The update also provides updated security services and includes the latest Security Updates.
QUOTE
That's why it's called combo
Heh, heh, yeah that's true...
MamaMoose had the symptom of the updater not installing...that's sometimes the case if something is missing...it just wont install. Launching the control panel helps to locate some of the missing components...if in fact anything IS missing.