OE6 e-mail go poof

A member of my office has had a series of problems with Outlook and has refused to let me switch him over to Thunderbird (I just had to get it off my chest). So today he loads of outlook and suddenly his inbox is empty but he still has an Inbox.dbx file which is over 2gb. After some reading online it seems OE has a problem with .dbx files that large and tends to corrupt them but I can't find any official answer on how to retrieve, shrink, or otherwise fix the problem. There are many $30 programs which say they can fix the problem but don't have reviews or even decent websites to back up their claims.

In my experience going around throwing money at random programs will get you nothing more than a black screen and unrecoverable hard drive after a massive virus infection so I figured I turn to my friendly neighborhood geeks before moving forward.

Does anyone have suggestions or experience with this problem?

I tried importing from Outlook to Thunderbird but the Inbox file was still empty. Maybe since Outlook doesn't recognize the e-mails Thunderbird can't see them or maybe the file is just empty, I'm not sure and I don't know how to check. The file is still 2gb large so I don't see how it could be empty but I've been proven wrong before.

I also tried using the tool from here but it didn't work.