Are you running Add Ins such as Snag It or Plaxo? Any Coms? Add Ins that are not compatible with Outlook 2003 cause the program to crash.
Also, running Terminal Services on the PC can cause Outlook to crash. To check for Add Ins and Coms, from your Outlook menu bar click on Tools, the Other tab, then Advanced Options. Also, try using the event viewer to troubleshoot this problem. To get to your event viewer, click on the start button, scroll to run, and then type in eventvwr at the prompt. When the event viewer opens, you see 3 logs to choose from: Application, System, and Security.