KMail not filtering incoming mail

So recently (and not due to a KDE update, as far as I can tell, although it 
did start after a reboot), KMail stopped filtering incoming mail.  All mail 
will go into the account's inbox. The filter logging window will show no 
activity. However, when I highlight those messages, and hit Ctrl-J, they will 
filter into their proper folders, and the activity will show on the filter 
log. Also, they filter very slowly, and the "akonadi_mailfil" process takes 
100% CPU.

Any ideas on how to trouble shoot this?

Thanks!

j