"CDiscoverDataManager::FilterDDR - Will not create CCR. This resource is already installed at this site."

Uninstalling the client and reinstalling it fixes the problem, but this is becoming more of a widespread problem.

There are two known causes of this problem:

1. This problem can be caused when a master image is built with the SMS client installed on it and then this image is used as the base image to build other machines (e.g. Ghost). Uninstalling and re-installing the client does fix the problem. Microsoft Knowledge Base Article 254735 "How to clean up duplicate computer IDs" also includes a procedure on how to overcome this. It is strongly recommended that everyone reads this Q article. You can use the following queries in addition to those in the Q article, to help you determine if you have duplicate GUIDs:

From MS PSS:

select distinct h.SMSID0 as SMSID, h.Name0 as "Machine Name", "h" from System_DATA as g, System_HIST as h where g.MachineID = h.MachineID and g.Name0 <> h.Name0 UNION select distinct g.SMSID0, g.Name0, "c" from System_DATA as g, System_HIST as h where g.MachineID = h.MachineID and g.Name0 <> h.Name0 order by SMSID, "Machine Name"

From Dave Yarbrough:

select distinct SMS_R_System.Name,SMS_R_System.OperatingSystemNameandVersion, SMS_R_System.ResourceDomainORWorkgroup, SMS_R_System.LastLogonUserDomain, SMS_R_System.LastLogonUserName, SMS_R_System.SMSUniqueIdentifier, SMS_R_System.ResourceId from SMS_R_System, SMS_GH_System_SYSTEM, SMS_G_System_SYSTEM where SMS_G_System_SYSTEM.ResourceID = SMS_GH_System_SYSTEM.ResourceID and SMS_G_System_SYSTEM.Name <> SMS_GH_System_SYSTEM.Name and SMS_R_System.ResourceID = SMS_G_System_SYSTEM.ResourceID

Author unknown:

select r.ResourceID,r.ResourceType,r.Name,r.SMSUniqueIdentifier,r.ResourceDomainORWorkgroup, r.Client from SMS_R_System as r, SMS_GH_System_SYSTEM as h,SMS_G_System_SYSTEM as g where g.ResourceID = h.ResourceID and g.Name <>h.Name and r.ResourceID = g.ResourceID

2. Andrew Buttigieg has found that this problem isn't just generated by duplicate SMSGUIDs. He has the same problem but all the SMS machines have unique SMSGUIDs. He uses Network Discovery and NT Remote Installation for his NT only site. The problem comes about when the "SMS Data Discovery Manager" doesn't have enough information about a resource (Network Discovery pulled the information  from DHCP but the machine is not online to get more info). For some reason, DDM merges resource records (the common element is that both machines (or more) held the same IP address at different times). The message: "CDiscoverDataManager::FilterDDR - Will not create CCR. This resource is already installed at this site." is very common. In the "Resource Names" of a resource record are the machines that got merged.