have you hyad Outlook 2003 on the system or have you updated to Windows XP
from an earlier system?
Things I'd try:
first:
1. On the taskbar, click Start, and then click Search.
2. In the Search Results dialog box, click All files and folders under
Search Companion.
3. In the All or part of the file name box, type outcmd.dat, and then
click Search.
4. In the right-hand pane, right-click the Outcmd.dat file, and then
click Rename.
5. Type outcmd.old, and then press ENTER.
6. Repeat steps 2 to 4 to rename "Extend.dat" to "Extend.old" and
"Frmcache.dat" to "Frmcache.old."
7. Start Microsoft Outlook.
8. On the Help menu, click Detect and Repair.
9. In the Detect and Repair dialog box, click to select the Restore my
shortcuts while repairing check box, and then click Start. Follow the
instructions on your screen to complete the repair process. The Detect and
Repair utility recreates the files you renamed.
Try a new profile. refer here:
http://support.microsoft.com/default.aspx?scid=kb;en-us;287072 (same applies
for Outlook 2000).
