I'm trying to get my system to checking with RHN using up2date but it always gives me a host not found error.

Here is my configuration, it seems all right!?
[root@ns root]# up2date --configure
0. storageDir /var/spool/up2date
1. networkSetup Yes
2. headerCacheSize 40
3. httpProxy No
4. debug No
5. useGPG Yes
6. networkRetries 5
7. removeSkipList ['kernel*']
8. retrieveOnly No
9. keepAfterInstall No
10. enableProxy Yes
11. gpgKeyRing /etc/sysconfig/rhn/up2date-keyring.gpg
12. proxyUser
13. proxyPassword
14. headerFetchCount 10
15. versionOverride
16. useNoSSLForPackage No
17. enableProxyAuth No
18. noSSLServerURL http://www.rhns.redhat.com/XMLRPC
19. noReplaceConfig Yes
20. sslCACert /usr/share/rhn/RHNS-CA-CERT
21. noBootLoader No
22. systemIdPath /etc/sysconfig/rhn/systemid
23. serverURL https://www.rhns.redhat.com/XMLRPC
24. pkgSkipList ['kernel*']
25. adminAddress ['root@localhost']
26. forceInstall No
27. fileSkipList []
28. retrieveSource No

Make sure that /etc/resolv.conf has correct entries:

search domain.com
domain domain.com
nameserver xxx.xxx.xxx.xxx
nameserver xxx.xxx.xxx.xxx

all is well there. I'm verifying with my host that I have the right name servers.