FC4 -- Mozilla Mail 1.7.12 Trashes Inbox

[Robert L Cochran <cochranb@xxxxxxxxxxxxx>]

This evening, I started Mozilla 1.7.12 under Fedora Core 4 and 
immediately clicked Window, Mail and Newsgroups to start Mozilla Mail 
just as I always did. It started up and then did something new to me: 
the Inbox viewers (both right-side panes) didn't fill up with a list of 
old emails as usual, and instead stayed blank. The hourglass stayed on 
for a while, about 60 seconds. Suddenly, ever email I have in the inbox 
between 02/22/2006 and now is trashed!

Only Inbox seems to be affected. The other folders seem okay.

I admit I had over 5000 emails in Inbox.

Is this a known issue? What's the fix for it if so?

Thanks

Bob Cochran