Worked another PCNS issue receiving the Event ID 6025 where the target could not be authenticated. I did some research and found that there was information on the Event ID 6025, but it dealt with the issue that is not SPN related. So I comprised a document dealing with the 6025 event id that involves problems with the SPN. Find it here.
I have updated this wiki to be more of a general 6025 Troubleshooting Article. This will provide guidance on the different flavors of 6025 that can be received.