Problem with file name too long

[GARETTE Emmanuel]

I'm using kolab 2.0 and from long time I've this kind of error on 
imapd.log file :

Dec 13 00:00:12 serv <error> imap[12641]: IOERROR: opening quota file 
/kolab/var/imapd/domain/k/kolab.com/quota/g/user.name^of^the^kolab^user.&AMk-l&AOk-ments 
supprim&AOk-s.[UNSHARED][UNSHARED][UNSHARED]user.[UNSHARED][UNSHARED][UNSHARED]user.partage^kolab.[UNSHARED][UNSHARED][UNSHARED]user.partage^kolab.Calendrier.[UNSHARED][UNSHARED][UNSHARED]user.partage^kolab.Calendrier: 
(36) File name too long

Dec 13 00:00:12 serv <error> imap[12641]: DBERROR: error fetching 
kolab.com!user.name^of^the^kolab^user.&AMk-l&AOk-ments 
supprim&AOk-s.[UNSHARED][UNSHARED][UNSHARED]user.[UNSHARED][UNSHARED][UNSHARED]user.partage^kolab.[UNSHARED][UNSHARED][UNSHARED]user.partage^kolab.Calendrier.[UNSHARED][UNSHARED][UNSHARED]user.partage^kolab.Calendrier: 
cyrusdb error

The directory exists in file system :

/kolab/var/imapd/spool/domain/kolab.com/user/name\^of\^the\^kolab\^user/\&AMk-l\&AOk-ments\ 
supprim\&AOk-s/\[UNSHARED\]\[UNSHARED\]\[UNSHARED\]user/\[UNSHARED\]\[UNSHARED\]\[UNSHARED\]user/partage\^kolab/\[UNSHARED\]\[UNSHARED\]\[UNSHARED\]user/partage\^kolab/Calendrier/\[UNSHARED\]\[UNSHARED\]\[UNSHARED\]user/partage\^kolab/Calendrier/

Some time my annotations.db is corrupted. For example :
DBERROR: skiplist recovery /kolab/var/imapd/annotations.db: 29DAE0 
should be ADD or DELETE

I need to restore annotations.db file.

This 2 problems could be related each other ?

Can I "blacklist" all mailboxes with name "[UNSHARED]" in cyrus conf or 
toltec ?

Regards