service imap pid 32188 in BUSY state: terminated abnormally

We have this error on my IMAP server :

    cyrus/master[32170]: service imap pid 32188 in BUSY state: terminated abnormally

We have a Debian sid with cyrus21 & openldap authentification.

I solve this with a :

    chmod 644 /etc/libnss-ldap.conf