Error from MOD referral containing spaces

[Chris Palmer <chris.palmer@pobox.com>]

I am having trouble processing referred MOD requests where the DN
contains spaces. It always fails with error 32 (not found).

Instance A is the master.
Instance B is a replica, type refreshAndPersist, and contains "updateref
ldap://instanceA:389"; following the syncrepl.
Both A and B are openldap 2.4.33 with identical configuration apart from
the sync and referral settings.

Updates to A replicate immediately and correctly to B (including those
with spaces in the DN).
Updates to B, without spaces in the DN, are referred to A, processed
correctly on A, and replicated correctly to B.

But: updates to B, *with* spaces in the DN, are referred to A where they
fail with error 32. The client (using Novell jldap 2009.10.07) does not
report an error, and of course the change is not replicated.

The MOD to B appears in ldap.log as dn="cn=first second,ou=.......".
Note the space between the two words of the CN. (This is also how MODs
sent directly to A appear, which do get correctly processed).

A network trace shows B generating a referral to A of the form:
   ldap://instanceA:389/cn=first%20second,ou=.....

The MOD referral to A appears in A's ldap.log as
dn="cn=first%20second,ou=....." with err=32.

I'm at a loss to know where to go from here, or even which component is
at fault. Can anyone help?

Many thanks
Chris