If you execute the command "/etc/init.d/S29netplug start" multiple times, you get multiple instances of netplugd. 
This is not the desired behaviour. We should only have one running netplugd.

The change has to be made in  package/netplug/S29netplug:
line 46:
-	start-stop-daemon -S -q -p /var/run/netplugd.pid -x /sbin/netplugd ${NETPLUGDARGS}

+	start-stop-daemon -S -q -x /sbin/netplugd -- -p /var/run/netplugd.pid ${NETPLUGDARGS}

Reason: 
If the start-stop-daemon gets the parameter -p /var/run/netplug.pid it will try to identify a running process by this pid-file but the file doesn't exist. As a result, every call of  "/etc/init.d/S29netplug start" starts a new netplugd.

--> The parameter -p /var/run/netplug.pid must be passed to netplugd.