LDAP over SSL Unsuccessful on 2003 DC, Working on 2008 R2 DC in Same Domain

LDAP over SSL Unsuccessful on 2003 DC, Working on 2008 R2 DC in Same Domain

I have a publicly signed UCC for LDAP over SSL in a test domain. It
contains the Server Authentication OID Extension and works fine on a 2008
R2 DC in the same domain. The CSR was generated on the 2008 R2 Server, but
contains a subject name matching the FQDN of the domain and SANs for the
2008 R2 DC's FQDN and the 2003 DC's FQDN.
When I attempt to connect from another system on the domain via ldp.exe to
the 2008 R2 DC via port 636 with SSL, it works fine. However, connecting
to the 2003 DC returns:
-----------
0x0 = ldap_unbind(ld);
ld = ldap_sslinit("testdc01", 636, 1);
Error 0 = ldap_set_option(hLdap, LDAP_OPT_PROTOCOL_VERSION, 3);
Error 81 = ldap_connect(hLdap, NULL);
Server error: <empty>
Error <0x51>: Fail to connect to afgtestdc01.
ld = ldap_sslinit("testdc01", 636, 1);
Error 81 = ldap_set_option(hLdap, LDAP_OPT_PROTOCOL_VERSION, 3);
Error 81 = ldap_connect(hLdap, NULL);
Server error: <empty>
Error <0x51>: Fail to connect to testdc01.
I have raised the SChannel logging level to "Log informational and success
events", the most verbose level available. However, the only event when
attempting to connect is 36867: Creating an SSL server credential.
To avoid a known issue where an incorrect certificate may be selected by
SChannel, I ensured the certificate is the only one in the Computer's
local personal store. I moved the intermediate and root CAs to their
respective computer stores. The certificate shows as valid in MMC.
What am I missing?