An HTTPS or TCP connection could not be made. Please wait for your network administrator to correct this problem, and try again later.

Windows Messenger 5.0 on Windows XP.

Exchange Server 2003 with Live Communications Server 2003 installed.

I have a certificate installed on the server for TLS over port 5061.

If I put the FQDN of the server into the SIP accounts page and tell it to
connect over TLS, then no problems at all.

I want, however for Messenger to look up the server using DNS SRV records.
I have followed the deployment guide and created the _sip_tls.f.q.d.n SRV
record in DNS, however when I set Messenger to "Automatic Configuration" I
get the error

"An HTTPS or TCP connection could not be made. Please wait for your network
administrator to correct this problem, and try again later."

...but it works manually.

Our email names are different to AD names (AD has an extra subdomain) and I
have told LC2003 to accept connections from both domains. Obviously this
may cause problems with the digital cert (it's in the name of the AD domain)
however the error when the FQDN for the server does not match the cert is
different.

Any ideas?