diff --git a/bristol/bin/startBristol.in b/bristol/bin/startBristol.in

index 551bf9c..df4be2e 100755

--- a/bristol/bin/startBristol.in

+++ b/bristol/bin/startBristol.in

@@ -65,6 +65,12 @@ COUNT=256

 LOGO=no

+#

+# Binaries we use

+VALGRIND_BIN="$(which valgrind 2>/dev/null)"

+CPUFREQ_BIN="$(which cpufreq-set 2>/dev/null)"

+

+

 #

 # The following is configured by the autotools process.

 #

@@ -158,9 +164,9 @@ for index in $*; do

 	fi

 	if [ $index = "-freqtweak" ]; then

 		FREQ=$2

-		if [ $FREQ != 0 -a -x /usr/bin/cpufreq-set -a $execme -eq 0 ]; then

+		if [ $FREQ != 0 -a -x "$CPUFREQ_BIN" -a $execme -eq 0 ]; then

 			echo Setting min CPU speed to $FREQ

-			cpufreq-set -d ${FREQ}

+			"$CPUFREQ_BIN" -d ${FREQ}

 		fi

 	fi

 	if [ $index = "-count" ]; then

@@ -206,6 +212,10 @@ for index in $*; do

 		execme=1

 	fi

 	if [ $index = "-valgrind" ]; then

+		if [ ! -x "$VALGRIND_BIN" ]; then

+			echo "valgrind binary not found" >&2

+			exit 3

+		fi

 		valgrind=1

 	fi

 	if [ $index = "-debug" ]; then

@@ -497,7 +507,7 @@ if [ $engine = 1 ]; then

 		fi

 	else

 		echo checking availability of TCP port $PORT

-		netstat -taln | awk '{print $4}' | grep $PORT > /dev/null

+		netstat -taln | awk '{print $4}' | grep ':$PORT' > /dev/null

 		while [ $? -eq 0 ]; do

 			echo -n "port looked busy, trying "

 			PORT=`expr $PORT + 1`

@@ -535,7 +545,7 @@ else

 					if [ $valgrind = 0 ]; then

 						brighton ${PREARGS} $args -port ${PORT} ${POSTARGS}

 					else

-						valgrind --leak-check=full -v --show-reachable=yes --track-origins=yes brighton $args -port ${PORT} ${POSTARGS}

+						"$VALGRIND_BIN" --leak-check=full -v --show-reachable=yes --track-origins=yes brighton $args -port ${PORT} ${POSTARGS}

 					fi

 				else

 					exec brighton ${PREARGS} $args -port ${PORT} ${POSTARGS}

@@ -567,7 +577,7 @@ else

 					exec bristol -rate ${RATE} -count ${COUNT} ${PREARGS} $args -port $PORT ${POSTARGS}

 				fi

 			else

-				valgrind --leak-check=full -v --show-reachable=yes --track-origins=yes bristol -rate ${RATE} -count ${COUNT} ${PREARGS} $args -port $PORT ${POSTARGS}

+				"$VALGRIND_BIN" --leak-check=full -v --show-reachable=yes --track-origins=yes bristol -rate ${RATE} -count ${COUNT} ${PREARGS} $args -port $PORT ${POSTARGS}

 				engstatus=$?

 			fi

 		else

@@ -591,8 +601,8 @@ fi

 sleep 1

-if [ $FREQ != 0 -a -x /usr/bin/cpufreq-set ]; then

-	cpufreq-set -d 250MHz

+if [ $FREQ != 0 -a -x "$CPUFREQ_BIN" ]; then

+	"$CPUFREQ_BIN" -d 250MHz

 fi

 # This could be a lot more intelligent but it will work. We need to remove any

 # dangling sockets. Alternatively just delete the files, the check for their