DBERROR: skiplist recovery /var/lib/cyrus/user/j/john.seen: ADD at 1D70 exists

[Jean Charles Delepine]

Hello,

After my /var partition became full this night my log keeps saying for
some of my users :

Aug  2 16:57:43 oban cyrus/imapd[1915]: login: localhost[::ffff:127.0.0.1] john CRAM-MD5 User logged in
Aug  2 16:57:43 oban cyrus/imapd[1915]: DBERROR: skiplist recovery /var/lib/cyrus/user/j/john.seen: ADD at 1D70 exists
Aug  2 16:57:43 oban cyrus/imapd[1915]: DBERROR: opening /var/lib/cyrus/user/j/john.seen: cyrusdb error
Aug  2 16:57:43 oban cyrus/imapd[1915]: Could not open seen state for john (System I/O error)
Aug  2 16:57:43 oban cyrus/imapd[1915]: open: user john opened INBOX
Aug  2 16:58:43 oban cyrus/imapd[1915]: Could not shut down filedescriptor 0: Bad file descriptor
Aug  2 16:58:43 oban cyrus/imapd[1915]: Could not shut down filedescriptor 1: Bad file descriptor
Aug  2 16:58:43 oban cyrus/imapd[1915]: Could not shut down filedescriptor 2: Bad file descriptor
Aug  2 16:58:43 oban cyrus/master[10117]: process 1915 exited, status 0

I'm running debian's cyrus21 :
ii  cyrus21-imapd  2.1.14-1       Cyrus mail system (IMAP support)

Can I do something to recover this john.seen ? And how can I know which 
*.seen are corrupt ?

Thanks a lot for any help.

           Jean Charles