Index: branches/blackosx/package/Scripts/Main/ESPpostinstall
===================================================================
--- branches/blackosx/package/Scripts/Main/ESPpostinstall	(revision 1732)
+++ branches/blackosx/package/Scripts/Main/ESPpostinstall	(revision 1733)
@@ -56,6 +56,8 @@
 
 targetResources="${targetVolumeChosenByUser}/usr/local/bin/"
 
+efiPartitionExist=0 # target volume does not have EFI system partition.
+
 echo "==============================================="
 echo "DEBUG: display script variables"
 echo "***************************"
@@ -92,14 +94,18 @@
 	echo "Confirm this is a GPT partitioned disk."
 
 	# Double check we can see the selected partition and it's of the right type.
-	# If the following script finds anything, it returns 1 to indicate failure.
+	# The following script returns either 0 or 1 to proceed, or 2 to indicate failure.
 
 
 	"$scriptDir"CheckProceed.sh "${targetVolume}" "${targetDeviceChosenByUser}" "${targetVolumeChosenByUser}" "${scriptDir}"
 	returnValue=$?
-	if [ ${returnValue} = 0 ]; then
+	if [ ${returnValue} -ne 2 ]; then
 		# OK to proceed
 
+		# Remember if the target volume has an EFI system partition.
+		if [ ${returnValue} -ne 0 ]; then
+			efiPartitionExist=1
+		fi
 
 		# Does a GRUB or Linux loader already exist in the disk's MBR?
 		# The script returns 1 if yes, 0 if no.
@@ -157,7 +163,7 @@
 				# OK to proceed
 				
 				# Mount the EFI system partition
-				"$scriptDir"MountESP.sh "${targetDisk}" "${targetVolumeChosenByUser}" "${scriptDir}"
+				"$scriptDir"MountESP.sh "${targetDisk}" "${targetVolumeChosenByUser}" "${efiPartitionExist}" "${scriptDir}"
 	
 				# Write the stage 2 loader to the root of the selected partition
 				"$scriptDir"WriteChameleonStage2.sh "${stage2Loader}" "${targetVolume}" "${targetDevice}" "${targetVolumeChosenByUser}" "${scriptDir}"
Index: branches/blackosx/package/Scripts/Main/Standardpostinstall
===================================================================
--- branches/blackosx/package/Scripts/Main/Standardpostinstall	(revision 1732)
+++ branches/blackosx/package/Scripts/Main/Standardpostinstall	(revision 1733)
@@ -56,6 +56,7 @@
 targetResources="${targetVolume}/usr/local/bin/"
 
 updateStage1=1 # by default update partition boot sector
+efiPartitionExist=0 # target volume does not have EFI system partition.
 
 echo "==============================================="
 echo "DEBUG: display script variables"
@@ -82,12 +83,17 @@
 "$scriptDir"InstallLog.sh "${targetVolume}" "Target volume = ${targetVolume} on ${targetDevice}"
 
 # Double check we can see the selected partition and it's of the right type.
-# If the following script finds anything, it returns 1 to indicate failure.
+# The following script returns either 0 or 1 to proceed, or 2 to indicate failure.
 
 "$scriptDir"CheckProceed.sh "${targetVolume}" "${targetDevice}" "${targetVolume}" "${scriptDir}"
 returnValue=$?
-if [ ${returnValue} = 0 ]; then
+if [ ${returnValue} -ne 2 ]; then
 	# OK to proceed
+	
+	# Remember if the target volume has an EFI system partition.
+	if [ ${returnValue} -ne 0 ]; then
+		efiPartitionExist=1
+	fi
 
 	# Does a GRUB or Linux loader already exist in the disk's MBR?
 	# The script returns 1 if yes, 0 if no.
@@ -182,7 +188,7 @@
 
 			if [ ${partitionScheme} = 1 ] || [ ${partitionScheme} = 2 ]; then
 				# Mount the EFI system partition
-				"$scriptDir"MountESP.sh "${targetDisk}" "${targetVolume}" "${scriptDir}"
+				"$scriptDir"MountESP.sh "${targetDisk}" "${targetVolume}" "${efiPartitionExist}" "${scriptDir}"
 			fi
 
 			# Check for another existing Chameleon installation on the same disk
Index: branches/blackosx/package/Scripts/Sub/MountESP.sh
===================================================================
--- branches/blackosx/package/Scripts/Sub/MountESP.sh	(revision 1732)
+++ branches/blackosx/package/Scripts/Sub/MountESP.sh	(revision 1733)
@@ -9,34 +9,43 @@
 
 # Receives targetDisk: for example /dev/disk2.
 # Receives installerVolume: Volume to write the installer log to.
+# Receives efiPartitionExist: either 0 or 1
 # Receives scriptDir: The location of the main script dir.
 
-if [ "$#" -eq 3 ]; then
+if [ "$#" -eq 4 ]; then
 	targetDisk="$1"
 	installerVolume="$2"
-	scriptDir="$3"
+	efiPartitionExist="$3"
+	scriptDir="$4"
 	echo "DEBUG: passed argument for targetDisk = $targetDisk"
 	echo "DEBUG: passed argument for installerVolume = $installerVolume"
+	echo "DEBUG: passed argument for installerVolume = $efiPartitionExist"
 	echo "DEBUG: passed argument for scriptDir = $scriptDir"
 else
 	echo "Error - wrong number of values passed"
 	exit 9
 fi
 
+# Check the first partition is actually type 'EFI'
+# as we could be checking a USB flash drive <4GB
+if [ ${efiPartitionExist} = 1 ]; then
 
-# Does the mountpoint exist?
-if [ ! -e "/Volumes/EFI" ]; then
-	mkdir -p "/Volumes/EFI"
-fi
+	# Does the mountpoint exist?
+	if [ ! -e "/Volumes/EFI" ]; then
+		mkdir -p "/Volumes/EFI"
+	fi
 
-# Mount '/Volumes/EFI' using the correct format type
-if [ "$( fstyp "${targetDisk}"s1 | grep hfs )" ]; then
-	"$scriptDir"InstallLog.sh "${installerVolume}" "Mounting ${targetDisk}s1 as /Volumes/EFI"
-	mount_hfs "${targetDisk}"s1 "/Volumes/EFI"
+	# Mount '/Volumes/EFI' using the correct format type
+	if [ "$( fstyp "${targetDisk}"s1 | grep hfs )" ]; then
+		"$scriptDir"InstallLog.sh "${installerVolume}" "Mounting ${targetDisk}s1 as /Volumes/EFI"
+		mount_hfs "${targetDisk}"s1 "/Volumes/EFI"
+	fi
+	if [ "$( fstyp "${targetDisk}"s1 | grep msdos )" ]; then
+		"$scriptDir"InstallLog.sh "${installerVolume}" "Mounting ${targetDisk}s1 as /Volumes/EFI"
+		mount_msdos -u 0 -g 0 "${targetDisk}"s1 "/Volumes/EFI"
+	fi
+else
+	"$scriptDir"InstallLog.sh "${installerVolume}" "Target volume doesn't have an EFI system partition."
 fi
-if [ "$( fstyp "${targetDisk}"s1 | grep msdos )" ]; then
-	"$scriptDir"InstallLog.sh "${installerVolume}" "Mounting ${targetDisk}s1 as /Volumes/EFI"
-	mount_msdos -u 0 -g 0 "${targetDisk}"s1 "/Volumes/EFI"
-fi
 
 exit 0
\ No newline at end of file
Index: branches/blackosx/package/Scripts/Sub/CheckProceed.sh
===================================================================
--- branches/blackosx/package/Scripts/Sub/CheckProceed.sh	(revision 1732)
+++ branches/blackosx/package/Scripts/Sub/CheckProceed.sh	(revision 1733)
@@ -6,6 +6,9 @@
 
 # Checks the selected volume is present and the disk is partitioned
 # Now also check for another existing Chameleon installation on the same disk.
+# Exit with 0 to indicate okay to proceed, no problems.
+# Exit with 1 to indicate okay to proceed, but note target doesn't have EFI system partition.
+# Exit with 2 to indicate not to proceed.
 
 # Receives targetVolume: Volume to install to (will be '/Volumes/EFI' if EFI install)
 # Receives targetDevice: Stores device number, for example /dev/disk2s1.
@@ -31,7 +34,7 @@
 if [ -z "$targetVolume" ]; then
 	echo "*** Cannot find the volume. Exiting."
 	"$scriptDir"InstallLog.sh "${installerVolume}" "FAIL: Cannot file the volume: $targetVolume."
-	exit 1
+	exit 2
 #else
 	#echo "DEBUG: Confirming target volume exists"
 fi
@@ -41,7 +44,7 @@
 if [ "$targetDevice" = "$targetDevice#*disk*s" ]; then
 	echo "*** ERROR Volume does not use slices. Exiting."
 	"$scriptDir"InstallLog.sh "${installerVolume}" "FAIL: $targetVolume doesn't use slices."
-	exit 1		
+	exit 2		
 #else
 	#echo "DEBUG: Confirming target device uses slices"
 fi