LDAP: "unused" & "uid missing"

Does someone know what this means? It looks to me like it got the UID, yet it complains ... ? Also, why does it complain about attributes being unused, yet I use prefetch, so they will be used?!

Log: [...] dovecot: auth: Debug: ldap(test@mydomain.tld,192.168.10.233,): result: mailStorageDirectory=/var/vmail mailUidNumber=2110 mailGidNumber=2110 mailQuotaStorage=10240 mailQuotaMessages=20; mailQuotaMessages,mailStorageDirectory,mailUidNumber,mailQuotaStorage,mailGidNumber unused

dovecot: auth: Debug: ldap(test@mydomain.tld,192.168.10.233,): result: mailStorageDirectory=/var/vmail mailUidNumber=2110 mailGidNumber=2110 mailQuotaStorage=10240 mailQuotaMessages=20; uid missing [...]

As mentioned, I use prefetch, so this is how my dovecot/dovecot-ldap.conf.ext is looking:

[...] #user_attrs = mailStorageDirectory=home=%$/%u, mailStorageDirectory=mail=maildir:%$/%u/maildir, mailUidNumber=uid, mailGidNumber=gid, mailQuotaStorage=quota_rule=*:storage=%$, mailQuotaMessages=quota_rule2=*:messages=%$

pass_attrs = uid=user, userPassword=password, mailStorageDirectory=userdb_home=%$/%u, mailStorageDirectory=userdb_mail=maildir:%$/%u/maildir, mailUidNumber=userdb_uid, mailGidNumber=userdb_gid, mailQuotaStorage=userdb_quota_rule=*:storage=%$, mailQuotaMessages=userdb_quota_rule2=*:messages=%$ [...]

Thanks