You generally see these errors when you have DFS replication issues on your domain controllers.
The first step would be to check your event logs (heck, that should always be your first stem) for FRS, and KCC error events.
Additionally I would run the
netdiag tools on each DC in your environment to verify that everything is ok with your AD infrastructure.
OK so EDIT
AFTER you get your replication and any other issues worked out (clean Error logs,
netdiag report no error. THEN you are going to need to go through and clean up the SYSVOL based on:
our last IT guy was ...special, he created a sysvol folder within the sysvol folder and that folder is shared. Problem? should I unshare that folder?
Get your replication issues sorted. Then you need to move that manual sysvol folder out of there and if it is sharing needed components, you need to recreate the share using a real file server.