Do you have a disjoint namespace? If so, take a look at this article (KB 948303),and consider installing the hotfix:
Active Directory System Discovery does not resolve the IP address of a computer that is discovered by System Center Configuration Manager 2007
SYMPTOMS
Active Directory System Discovery does not resolve the IP address of a computer that is discovered by Microsoft System Center Configuration Manager 2007 when the computer is operating in a disjoint namespace. This behavior prevents the Data Discovery Records (DDRs) from being generated.
Error message: GetIPAddr - getaddrinfo() for <FQDN> failed with error code 11001.
http://support.microsoft.com/?kbid=948303