We have a domain (domain.com) and a subdomain (subdomain.domain.com)

We have Netware 5.1 in production. We created the subdomain (TID10016522).
All works fine.

We installed Netware 6.5 in a new environment (laboratory) with Netware
6.5 only. We created a subdomain (TID10016522). All works fine.

We installed Netware 6.5 in production. We transfered DNS from Netware 5.1
to Netware 6.5. All works fine except the "delegation". When I go to
nslookup and type "ls -t subdomain" I always get a BAD ERROR VALUE.

Is there a known issue anywhere?
Thanks