If the connection is showing as Established, then the problem is not the duplex setting. We don't recommend changing this, in fact I've never seen this cause a problem.
Try doing an "nrstop;nrstart" on the sensor to restart the services, do you see any Route Up/Down signatures appear? If not, then your CSPM database is probably corrupted, so go to the Troubleshooting Toolkit from the Start menu, and restore the database. Make sure you File - Export your cxonfiguration off first, then File-Import it back in after the restore is done.
If you do see Route UP/Downs but nothing else, then your sensor is probably not seeing any traffic. If you do a Snoop on the sniffing interface (snoop -d iprb0) do you see traffic? Is it all broadcast/multicast or is there unicast traffic? What level of alerts are you sending to CSPM (check under the Filtering tab in CSPM, set it to Medium).
