Is this a new problem with KMail?

Recently I had a nicely working KMail setup, after setting up another box on 
the network to run fetchmail to feed my ISP's POP mail to KMail via a local 
IMAP account. There was the occasional hiccup, but nothing to get hot under 
the collar about.

Then I decided to import some older e-mails. I knew that KMail has trouble 
with e-mails that have been imported from its own archive so I extracted the 
archive into a new directory and imported the e-mails from there. I've found 
that to work well before.

Then I started getting duplicates and other problems, so eventually I archived 
what I had, created a new user directory and set it up from scratch, lastly 
importing e-mails and directory structure in the same way as above.

I had trouble creating the IMAP account in KMail, until I first created a POP 
account with my ISP (but not using it to fetch e-mails) and only then creating 
the local IMAP account. Now I find that, when KMail fetches e-mails from my 
server and filters them, they go into their proper folders but the message 
totals in the folder list are not incremented. That means I have to click on 
every folder and hit + to see if anything new is there.

I haven't come across this before. I wonder whether it's another throw-back to 
something going wrong in the import operation.

I mention this in case someone has an idea from it: either to advise me on 
working around it or to suggest an area of investigation. Would akonadi fsck 
help? I've never found it to do anything here so I don't automatically think 
of it.

-- 
Regards
Peter