Other options:
1) Create a new Outlook profile on that computer without deleting the existing one. Configure it with the same settings (Exchange or POP settings, etc.). You'll have to go to Start -> Control Panel -> Mail -> Profiles to create the new profile and to select the option to ask for a profile when starting up Outlook.
2) Open the new profile and see if the problem still exists. If yes, then go to Step 3. If no, then go back to Start -> Control Panel -> Mail -> Profiles, and select the new profile as the default one to load.
3) Make sure Outlook has the latest Service Pack. Outlook 2003's latest Service Pack is 3.
4) Try printing to a different printer. If the same thing happens, go to Step 5. If not, then the problem is the printer driver. Uninstall it, download the latest update for the printer, and reinstall it with the update.
5) Try logging in as a different user. I'm not sure if your corporate environment is using roaming profiles, but if it is, then this could eliminate a few things. Open up Outlook under the different user account and try printing an e-mail. If the problem doesn't occur here, then the user's roaming profile might be corrupt. To confirm this, log onto another PC with the user's account that is having the problem, and try to print. If the problem exists, then yes, indeed, their profile is corrupt. Start rebuilding that profile!