Yes, multiple 'minerd' processes are launched at startup, so 
```su - ${USER} -c "${CPUMINER} -c ${CFG_FILE} -t 1 2> ${LOG_FILE}" & echo $! > ${PID_FILE}``` don't work
and ```start-stop-daemon``` don't work either.

I might say a mistake, but ```pidof``` comes from busybox ? busy box is not available before DSM 4.1 ?