dovecot - Jan 2014 - Wrong file accessed after file was renamed because of wrong size

I'm migrating from Courier-IMAP. On first access of folders I get this log
(slightly anonymized):

Jan  1 18:38:27 mail dovecot: imap(username): Error: Cached message size smaller
than expected (1452 < 1668)
Jan  1 18:38:27 mail dovecot: imap(username): Error: Maildir filename has wrong
S value, renamed the file from
/var/vpopmail/domains/domain/username/.maildir/cur/1206559119.14350.mail,S=1452:2,RS
to
/var/vpopmail/domains/domain/username/.maildir/cur/1206559119.14350.mail,S=1668:2,RS
Jan  1 18:38:27 mail dovecot: imap(username): Error: Corrupted index cache file
/var/vpopmail/domains/domain/username/.maildir/dovecot.index.cache: Broken
physical size for mail UID 161
Jan  1 18:38:27 mail dovecot: imap(username): Error:
read(/var/vpopmail/domains/domain/username/.maildir/cur/1206559119.14350.mail,S=1452:2,RS)
failed: Invalid argument
Jan  1 18:38:27 mail dovecot: imap(username): Disconnected: Internal error
occurred. Refer to server log for more information. [2014-01-01 18:38:27] in=135
out=63515

This is the same in 2.2.6 and 2.2.10.

Greetings,

Eike

 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: This is a digitally signed message part.
URL:
<http://dovecot.org/pipermail/dovecot/attachments/20140101/b362de17/attachment.bin>