How did you "restore"? It sounds like you may have damaged your mail
profile.
First, right-click and choose Close. If that doesn't work, try File>Data
File Management, select the PST and click Remove. If that doesn't work, use
Control Panel>Mail>Show Profiles>Add to add a new mail profile, pointing it
at your current PST.
I did a O2003 Restore from Outlooks backup program. All of Outlook 2003 works
great except that the .pst file is 2X size at 800M instead of 400M (I use it
for my business).
I'll try your hints and report back and thanks Brian.