CIW install after CD install

I am in the process of testing the deployment of Office
2003 (without Outlook & Access) using CIW. Everything
works fine, except for machines that have previously had
Outlook 2003 installed from CD. When the CIW package
runs, it quickly runs through setup and completes. When
looking at the install log, it completes successfully,
but no programs (i.e. Work, Excel and PowerPoint) get
installed. The machine is left with Outlook 2003 and
nothing else? If I manually uninstall Outlook 2003
before installing the CIW package, all programs will
install successfully. Is there a way to install CIW
package without manually uninstalling Outlook 2003?
Testing with previous versions of Outlook work without
issues. The old version of Outlook remains while Word,
Excel and PowerPoint update to version 2003.
Any help would be greatly appreciated, before I go
completely crazy!