My computer froze and when I restarted it I discovered that my personal folder inbox has no folders. I also can no longer access the e-mail that I get in the Inbox folder. I ran the PST Repair Tool and it told me that I have 76 folders and 5,400 messages, but when I open the restored file I can't see a single message.
Sometimes you have to run the Inbox Repair Tool (SCANPST.EXE) repeatedly over the same data in order to get all of the problems fixed.
While you're at it, make sure that you check your hard drive for errors and make sure you have plenty of hard drive space.