Remove the zone wire from one of the stations that's got full time power and check it again. I've found that on some of the Hunter clocks, if the wires are stuck in too far they can come into contact with something inside the controller or module that is always hot. I know this is the case with the XC, not sure about the ICC, but if you remove a station wire, you can confirm that to be the cause or rule it out.
Also, Hunter modules do go bad. I've replace several PCM's because of similar problems, I wouldn't be surprised if that was the case here.