The patch I originally sent works only for MODRDN operations, but causes a segfault on plain old ADD operations in some cases.
This is caused by the hdb_dn2id_children function trying to update dkids inside a non-initialised structure. I figure that if we don't have the structure we don't need to update it, since this function is mostly a "search" function. Hope that makes sense.
A new patch is here: ftp://www.openldap.org/incoming/openldap-dn2id-modrdn-idlcache-sub-delete-2.patch
Jonathan