Threaded mails do not display - v0.7.1

[philip_rhoades]

People,

I have a folder with a few dozen mails in it - threading has been working fine on that folder until today, if I look at the mails in threaded mode - some threads are missing - if I go to list display, the missing mails are visible again.   I tried deleting the Dovecot index files but that didn't change the problem.  Is there a know issue with this?  I think I might have seen this before but not really twigged to what was going on.

Thanks,

Phil.