Windows 2008R2 failing to update DDNS records

If you are running an environment with dynamic DNS, record scavenging, and 2008R2 servers; you may notice records disappearing from time to time. There is a bug in 2008 that causes systems to fail to maintain their records if you make changes to the DNS server IP's that the system uses. If you run ipconfig /registerdns, it forces the system to update and all is well. If you want to get around having this problem with a more permanent solution, Microsoft released this patch recently (kb 2520155).