This happened on my installation too, and was caused by Windows Installer (I
hate that damn thing!).
What is happening is every time you load the app, Installer is adding
components it needs, but for some reason it 'forgets' them so next time you
load, it installs them again. Takes about 2 minutes.
I also had other problems and here was the cause/solution:
It looks like it happens if your old Office 2000 installation is not in full
working order when you install Office 2003 over the top of it.
Originally when I installed, here is what happened:
1. Installed Office 2003 over Office 2000 but installation failed
2. 2003 installation rollback caused 2000 not to work properly - Outlook
XP wouldn't open without Windows Installer asking for the CD
3. What I should have done is give it the Office 2000 CD and let it fix
the installation, but I didn't as I didn't think I needed Office 2000
working
4. I then installed 2003 over 2000 which strangely didn't offer to
perform an Upgrade, just a Clean Installation
5. The result is Outlook didn't offer to migrate my previous settings,
Windows Installer kept flashing up when opening Word, Outlook, etc. and my
mail downloaded to nowhere as per this thread
Here's how I fixed it:
1. Used System Restore to go back to the broken Office 2000 installation
2. Put the Office 2000 CD in when prompted to allow Windows Installer to
fix 2000
3. Still some problems with 2000 so did a complete reinstall from Control
Panel>Add/Remove Programs
4. With 2000 working, I *then* installed 2003 over the top
5. It correctly offered to Upgrade, Outlook correctly migrated settings,
and all problems disappeared once it finished
Hope this helps.