Identity Manager 4.5. Bidirectional eDirectory driver connected to an eDirectory 8.8 SP8 (build 20808.02).

Fresh install of eDirectory, ChangeLog, schema extended with clschema.sch.

Just after the first pooling, the driver connection reports the error:
DrvNAMeDir PT: DrvNAMeDir: EdirPublisher - Initiating agent registration...
DrvNAMeDir PT: DrvNAMeDir: LDAPInterface.registerDriverInstance() : Exception occured while registration - Other
DrvNAMeDir PT: DrvNAMeDir: Cannot establish ldap connection to remote eDir yet ... waiting for 30 sec.

On the target eDirectory, with LDAP ndstrace, we can see the following error:

DoExtended: Extension Request OID: 2.16.840.1.113719. Sending operation result 80:"":"insufficient space (-1)" to connection 0xe27c00

Trustee rights checked, installed the last version of the driver and changelog.

Any idea?