Sorry for the long post, this is how Microsoft sent it to me.
(Microsoft Wrote) >>>
Based on my experience, you may have to reinstall Outlook 2003 in some cases such problem happens. Before you do that, please follow steps below to narrow down this issue:
Search and Rename the Outlook Cache Files:
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Search for the following four files and rename them by changing the file extension from ".dat" to ".old". These four files are temporary cache files that Outlook 2002 loads on startup. (Be sure to check the "Search hidden files and folders" box under "More advanced options" if you are using Windows XP)
outcmd.dat
extend.dat
frmcache.dat
views.dat
Generally the files can be located in the folder C:\Documents and Settings\<LogName>\Local Settings\Application Data\Microsoft\Outlook\ If they are not there, please perform a whole system search for them.
Note: The folder is hidden by default. Please use the following method to show it:
a. From the Start menu, go to Settings-->Control Panel-->Folder Options.
b. Go to View tab and select "Show hidden files and folders". The hidden folder will be shown then.
c. Start Outlook to see if the problem is resolved.
If the issue persists after your renaming cache files, please continue with the next steps:
Outlook Safe Mode:
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1. Click Start, and click Run.
2. In the Open box, type: "Outlook /safe" (without the quotation marks)
Notes: There is a space character between Outlook and the forward slash (/).
3. Click OK.
4. If the problem doesn't occur this time, please select Tools->Options->Other->Advanced Options->Add-In Manager and then clear all the check boxes, add one check back each time to the list of Add-In, restart Outlook, and repeat the above procedure. Once the issue reappears again, we can determine which add-in causes this problem and then disable it.
If error still happens, try to create a new profile and test this issue again:
(a) Close Outlook 2003.
(b) Click Start menu, point to Settings and choose Control Panel. Double-click the Mail icon.
(c) Click Show Profiles and then click Add. In the New Profile dialog box, type a descriptive name for the new profile in the Profile Name box, and then click OK.
(d) In the E-mail Accounts dialog box, click "Add a new e-mail account", and then click Next.
(e) Select the appropriate server type for your new e-mail account, and then click Next.
(f) Fill in the appropriate information as prompted, and then click Next and Finish as needed.
(g) Click the "Prompt for a profile to be used" option and click OK. This way, you will be prompted for a profile when starting Outlook.
(h) Restart Outlook and select the new profile. Reconfigure your mail account and test the issue again.
More information about how to create a new profile is documented in the following Microsoft Knowledge Base (KB) article:
Q287072 OL2002: How to Create a New E-mail Profile for Outlook
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http://support.microsoft.com/default...;en-us;q287072>
Please note: This article also applies to Outlook 2003