Strange Thunderbird inbox
My inbox in Thunderbird suddenly contains about 29 000 messages, but there were only 20 there when I open it. I tried compacting it to no avail. It seems like all messages, including deleted ones are included. I checked it's size and inbox size is about 75 k and inbox.msf is 5 k. So I moved the 20 files to other folders. Then I deleted the inbox.msf file. No result.
Thunderbird seems to work normally, though. It is a pop3 account. What can I do short of uninstalling T-bird and reinstalling it?
Windows 7 64b SP 1.