file-system problems after update from 2.0.16 to 2.1.9

[Alexander Czernay]

I just upgraded my Cyrus-IMAP from 2.0.16 to 2.1.9. At ./configure I 
added --enable-fulldirhash and also compiled Berkeley4.1.24 in.

It all worked well, but now I get some strange errors in the logs:

IOERROR: opening /var/imap/user/c/czernay.seen: No such file or directory
DBERROR: opening /var/imap/user/c/czernay.seen: cyrusdb error
Could not open seen state for czernay (System I/O error)

Investigating the file-sytem I found that only directories with capital 
letters exist under the /var/imap/user tree. But these are all empty!

I have the very same problem with the sieve directory tree.

Have I done anything wrong? Can I just rename the directories? Isn't all 
that no supposed to be saved in dbs?

Thanks for any help!

Alexander