Quick description: There are three domains DomainA, DomainB, DomainC.
No trust relationships between any of the domains.

My users are in DomainA.
Originally this server was in DomainB.
About 6 months ago the server was moved to DomainC. The logon script was not changed at that time but still worked even though it referenced a user from DomainB.
Last week the script stopped working. No obvious network problems were occuring.
I made the changes illustrated in the posts above and the mapping worked again. This time, however, a user account from the local computer was used instead of Domain based user credentials. Also, QUOTES were added around the domain\username due to a unique character being in the server's name.