We tested this against Notes/Domino without any issues at the time of development, and I just retested it against Notes 6 without a problem.
Is this on the same box with the same service account credentials etc?
What does the job log for the distribution section look like?
Mine looks like this, with the email "To:" just referencing "Gareth Horton" and looking up against the Notes LDAP:
Operation Status Start Stop Message
- Email Completed 05-22-2008 17:21:56 05-22-2008 17:22:13 Test From AD with Notes LDAP Lookup
to Gareth Horton
subject Test From AD with Notes LDAP Lookup