[Dovecot] Second user problems

I have dovecot (0.99.14 under FC4) set up and working beautifully for my mail, handing on to procmail, and handling many subfolders. Today I needed to set up a second user. I added his account in kmail and created a sub-folder, but no sent-mail, trash etc. were created. I have sent test messages and /var/log/maillog says they have been processed, but they are not arriving in his inbox. /var/log/mail.info shows that he has logged in to dovecot. He has a simple .procmailrc to handle the one subdirectory.

I'm sure that it must be something I've missed in dovecot.conf, but I can't see anything there that shouldn't work just as well for him as it does for me. Any pointers?

Anne