Should not be possible to get multiples started up via the init.d script:
bnesbitt 32143 0.0 0.0 24644 1188 ? Ss 13:09 0:00 /usr/local/sbin/gpsdproxy -i MNC-TestPC-1 -t 10 -h obviously.com -p 5151 -s 127.0.0.1 -r 2947 -f /var/run/gpsdproxy.pid -d 3 -b
bnesbitt 32149 0.0 0.0 24644 1180 ? Ss 13:10 0:00 /usr/local/sbin/gpsdproxy -i MNC-TestPC-1 -t 10 -h obviously.com -p 5151 -s 127.0.0.1 -r 2947 -f /var/run/gpsdproxy.pid -d 3 -b
bnesbitt 32155 0.0 0.0 24644 1180 ? Ss 13:10 0:00 /usr/local/sbin/gpsdproxy -i MNC-TestPC-1 -t 10 -h obviously.com -p 5151 -s 127.0.0.1 -r 2947 -f /var/run/gpsdproxy.pid -d 3 -b
/etc/init.d/gpsdproxy start
/etc/init.d/gpsdproxy status
/etc/init.d/gpsdproxy stop
It appears that on Ubuntu 11.04 at least that /var/run/gpsdproxy.pid never gets created. The "stop" action considers failure OK. So the "start" action just makes more proxies. There is no "status" action to check the PID.