This info came straight from microsoft:
Cause:
This behavior can occur when the Transmission Control Protocol/Internet Protocol (TCP/IP) configuration is using the incorrect IP address for the Domain Name Service (DNS) or WINS server on your network, or when no name server IP addresses are specified.
Resolution:
To resolve this behavior, make sure that the IP addresses of the DNS and WINS servers on your network are specified correctly in your TCP/IP settings.
More Information:
To verify that the relevant IP addresses are correct, follow these steps:
1.On the desktop, right-click My Network Places, and then click Properties.
2.Right-click the appropriate connection object, and then click Properties.
3.Click Internet Protocol(TCP/IP), and then click Properties.
4.Click Advanced.
5.Click DNS, and then click Add. In the DNS Server box, type the IP address of the DNS server to use to resolve DNS fully qualified domain names (FQDN), and then click Add.
6.Repeat this procedure to add the IP addresses of each DNS server on your network. After adding all DNS server IP addresses, click the arrow buttons to arrange the list of IP addresses in the preferred order of use.
7.Click WINS, and then click Add. In the WINS Server box, type the IP address of the WINS server to use to resolve NetBIOS names, and then click Add.
8.Repeat this procedure to add the IP addresses of each WINS server on your network. After adding all WINS server IP addresses, click the arrow buttons to arrange the list of IP addresses in the preferred order of use.
9.Click OK in the open dialog boxes to close them and to save the new settings.
The WINS portion may not apply in your exact situation. However 1 other related article said to check the same thing basicly. Make sure the IP address are correctly pointing to the right DNS server. Check your advanced TCP/IP properties in DNS tab.
Hope this helps
Jason