This will only work for x86 wss3. x64 wss3 is not supported in glaxy 6.1.
You will have to create the following values on your sharepoint server.
1. Create the following registry key on your sharepoint server.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\6.0
2. Create the following value under this newly created registry key.
Type: String
Name: Sharepoint
Value: Installed
3. Use CD1B to install the sharepoint document ida.
You may receive an error message during the install of the SharePoint document ida "REGASM is unable to register sp2k3docserver.dll"
This message is ok, once the install completes you will not be able to perform any backups until service pack 4 is also loaded on the SharePoint server.
4. Service Pack 4, and update 900 must be installed to support SharePoint 2007.
Currently SharePoint document backups are only supported on SharePoint 2007.