Paul-
I think the problem may be that I had more than one instance of tRio running (if that's possible). I'm not sure how or why, since I always started and stopped the app using trio.sh. I noticed that the receivers kept working after running 'trio.sh stop'
The problem was exasperated by my lack of Linux experience. I couldn't see the process running using 'ps -ax | grep trio'. I traced the problem to the long startup command, which gets truncated on the 80th column by the ps command. Once I added '--cols 120' to the ps command, I saw trio processes.

One more question- when I run, I see 31 PIDs associated with trio. Is that correct? They all disappear when I run 'trio.sh stop'.

Again- thanks for the help.
-hans