I have a 3750 that is in DCR and showing up in device center, but it is not in the Device Fault Manager?
Running: Device Fault Manager 3.0.4 and CiscoWorks Common Services 3.1.1
Then you need to add the device to ACS first. Once you do, log out of LMS, then log back in. Then go to DFM, and you should be able to find the device, and manage it.