Excel/Outlook Error reporting

Whenever I shut down Excel XP(SR-2) and have Outlook XP(SR-2) running at the same time, Excel produces an error and wants to send an error report to microsoft. This happens with a number of files and sometimes even if I don’t have anything open. If Outlook isn’t open everything works normally and no error reports are created. The system is Windows 2000 PRO. Has anyone come across this or does anyone have any ideas how to resolve this ?