I havent herd county drop tones on the 154.37 frequency for Norristown. they're only dispatching on the 800. Are they not using the Minitor channel anymore?
Wirelessly posted (Mozilla/5.0 (X11; Linux i686; U; en-US) Gecko/20081217 Vision-Browser/8.1 301x200 LG VN530)
Is it possible that they changed their CTCSS/DCS recently? If they did, and you haven't changed it in your scanner, you won't hear anything. Just throwing an idea out there for you.