[kiler129]

What about Kindle 4 non-touch? I disabled updates by editing /usr/bin/process_update
I've changed two parts:

if [ $BATT -ge ${_MIN_BATT} ]; then
		#msg "Immediate update requested.  Starting" I
                msg "Trolololo ... big brother disabled by user"
                
		# Kill any running updatewaits processes
		killall updatewait 2>/dev/null
                
                #Disable forced updates [send no update file code]
                exit 130
                
		${_UPDATE_WAIT} $@
		exit $?

# Start updatewait in background and exit
	#${_UPDATE_WAIT} &
	#msg "Started ${_UPDATE_WAIT}" I
	msg "Trying to start update-spy - trololo, disabled by user"
	exit 130

Code #130 mean "no update file" so it should be safe.