PC slow login- Sites and Services correct but incorrect SRV record

A site that had recently been re-IPed was complaining about slow logins on their PCs- it could take a user up to 15 minutes to log in.

Sites and Services was setup correctly with the proper subnet and DC assigned to the site.

We found that there was an erroneous entry in DNS which was causing the machines to use the wrong DC for authentication.  The entry was found here:

Forward Lookup Zones
[our domain]
DomainDnsZones
_sites
[site name]
_tcp

There were two _ldap entries in this location.  One pointing to the correct DC and one to an incorrect DC.  Removing the incorrect record resolved the issue.

Note:  it is a good idea to check all the Sites entries in DNS to make sure that there are not other erroneous _ldap entries