Most WSUS clients show status 'Not yet reported'

I have migrated from WSUS 2.0 to 3.0 and it was working properly without any issues. After that I migrated WSUS 3.0 to a new server for a prerequisite of SCCM 2007 and this migration was performed by making it a replica server and then eventually making it standalone and decommissioning the original server. After that I am not able to get it to work properly. SCCM 2007 is working without any problem and WSUS also responds fine, but the clients are not able to report. I have tried many things to get clients reporting but I end up getting errors in the log like:

2007-10-18 12:00:33:872 1104 75c PT WARNING: Cached cookie has expired or
new PID is available
2007-10-18 12:00:33:872 1104 75c PT Initializing simple targeting cookie,
clientId = c0ec9880-ab96-4a1d-8612-22ee02f8dbec, target group = , DNS name =
napait800937.tdc.internal
2007-10-18 12:00:33:872 1104 75c PT Server URL =
http://NPSCCM101/SimpleAuthWebService/SimpleAuth.asmx
2007-10-18 12:00:33:888 1104 75c PT WARNING: GetCookie failure, error =
0x8024400D, soap client error = 7, soap error code = 300, HTTP status code =
200
2007-10-18 12:00:33:888 1104 75c PT WARNING: SOAP Fault: 0x00012c
2007-10-18 12:00:33:888 1104 75c PT WARNING: faultstring:Fault occurred
2007-10-18 12:00:33:888 1104 75c PT WARNING: ErrorCode:ServerChanged(4)
2007-10-18 12:00:33:888 1104 75c PT WARNING: Message:Server rolled back
since last call to GetCookie

Any help would be appreciated.

I was able to work on the same by getting rid of WSUS. I started working it on from scratch and the all the settings are reconfigured back from start. I had also wiped out WSUS foler and then start syncing with updates. I had installed old updates once again and in that only found fix that sorted out the issue with WSUS. The sync is not working and there is no problem at all. I will recommend you to reconfigure your settings once again and then check back. I am sure this will be one of the most quickest way to deal with the issue that you are facing.

Reconfiguring WSUS client will resolve the issue. It looks some improper settings is causing the problem. You have to go in Local Group Policy Editor. In that go in Windows Update and from the right side select Configure Automatic Updates. Enable it and provide proper settings to activate it properly. Later on come the client computer configuration. Ensure that you are providing the right computer names. The next process is to configure Automatic Updates. Keeping the settings on automatic is better, because here you don't have to checkup the updates every now and then.

Have you updated WSUS to 3.0 SP2. If not then go ahead with the fresh updates. This will add more stability in the tool offering you simple way to manage your Automatic Updates. I am giving you a link below which has a download link available for the same. You can run the same and update WSUS easily on your system. The second thing you can do is checkout the connectivity issues. This occur sometime due to internet configuration. You will have to re-verify the same once again and see whether it is actively working or not. Go in Services and restart Automatic Update Services.

An update for Windows Server Update Services 3.0 Service Pack 2 is available