Vista - Windows Live Mail: Header and message don't match

I have the same header/message mismatch problem described in this thread, but only in one message store folder. I click on a header for a message from, say, 12/1/2008, and what opens is instead a message from, say, 5/16/2004. There is no rhyme or reason to it--at least none that's apparent to me.

I assume the process outlined in the past thread will fix it. But since nothing but this one folder is giving me problems, I wonder if I can just have that one folder rebuilt, because all the processing time and then manual moving of messages is something I'd rather avoid.

This particular folder wasn't created in Windows Live Mail, but has migrated from Outlook 2000, to Windows Mail, and now to Windows Live Mail (and let's see...four PCs along the way!). The folder got hashed at some point when I was using Windows Mail, and then the mixed up data got faithfully imported when I upgraded to Windows Live Mail.

By the way, the problem folder has more than 18,000 messages in it. Is that perhaps part of the problem, i.e. is there a limit? Or perhaps was there a limit in Windows Mail and that's why my data got pureed?

Thanks to any and all.