pipercub--
Try either compacting or deleting the folder.dbx as described in these two links. http://social.answers.microsoft.com/...5-a40940aec062
http://social.answers.microsoft.com/...8-09502093b370
If no success, perhaps some ideas here
http://www.microsoft.com/windows/ie/...orruption.mspx

Once you have an inboxold.dbx file, you may be able to recover the contained messages and export them into your new inbox.dbx. (The following is from http://www.skud.net/board/viewtopic.php?f=6&t=57 )
"Importing your Outlook Express email messages

A step by step guide to help you to import your saved email into Outlook Express.

Close all programs running on the system.

Click Start.

Click Programs.

Click Outlook Express.

Click on the File menu located at the top of the Outlook Express screen.

Scroll down and select Import.

Scroll across and select Messages.

Outlook Express will then request you to choose the type of mail files they are.

Select the version of Outlook Express that you have installed and click Next.

Outlook Express will then ask if you want to import from a main identity or a mail store.

Only select the Outlook Express Store Folder option if you have moved your *.dbx files after exporting them. If you have moved your *.dbx files to another folder then select the Outlook Express Store Folder option and point Outlook Express to the folder that contains the *.dbx files that you want to import. Otherwise, leave the default setting and import your email from your main identity. If you have multiple identities you will be prompted to choose which identity you want to import your email from."

If you are willing spend $27 this might help, though there may be a trial period.
http://www.oemailrecovery.com/outloo...-recovery.html