How many sensors do you have per subnet? It may well be that the server has instructed the sensor to go to sleep.
Check the RSSensor_out.log for any messages that migh shed some light...
Where is the RSSensor_out.log stored?
1 RS per subnet, plus I have it on our 2 DHCP servers.
What is strange these RS agents appears under the uninstalled area (Rogue System Detection > Rogue System Sensors > Uninstalled) and the Active location, why is this do you think?
Where are you seeing the status "unknown"? I just looked at my sensors and can't figure out where I would see that.
If you sensors are going to sleep due to max sensors per subnet, their status should be "Passive" and not unknown. If "unknown", I would suspect that your ePO server is unaware of what the sensor has been up to lately. You could try restarting the rssensor service on the sensor machine and see if that helps.
There's also a server task to "RSD: Update Sensor Deployment Client Tasks". If you have this enabled and a sensor deployment did not fully succeed, I've seen this cause some issues with sensors.
The log should be in the RSS install folder - Program Files\McAfee\RSD Sensor by default. I' check that before anything else - there may be communication problems.
Now that you mention the uninstalled area, things make a bit more sense. This is what has happened to me when a sensor doesn't update properly. (or ?something?)
For these "uninstalled" sensors, uninstall the sensor software and remove all sensor deployment properties for this machine, then re-deploy from fresh. That should fix it up. If you're seeing this on a larger number of sensors, this procedure might be tedious but for a couple it's not too bad....at least it works.
you will find the RSSensor_out.log per default in "c:\Program Files\McAfee\RSD Sensor\" ...