I have a RS PRO-197. I'm located in NC so I have it programed with the VIPER/WAKE COUNTY digital system. For some reason, in the past few months, I will stop receiving certain digital signals. For example, Raleigh PD will just go away while Wake County Sheriff, NCSHP and EMS are still being received. Then sometime later I start hearing RDP again. (It's not just RDP, just an example). I've reprogramed the radio several times but get the same result. The signal meter indicates 3-4 out of 5 on the 'S'-meter so I have a strong signal. Besides, if it was week I would assume I would receive nothing digital. All analog stations (I.e., AIR, HAM, etc.) work just find. Any ideas?