[Galaxy Y GT-S5360 General] kurotsugi:
you'll need to modify the script a bit.

#!/system/bin/sh
# kuro akuro: new data2sd method
# copyright@mycat (2012) - lol...i'm just joking. no copyright or whatsoever
# contact : kaze.noichi17@gmail.com

# v.1 - first release
# v.1.1 - automated system, new build,

LOG_FILE=/data/kuro_akuro.log
if [ -e $LOG_FILE ]; then
rm $LOG_FILE;
fi;

# the preface
echo "==========================
# TWEAK AKURO-LOG FILE #
==========================
in the name of Allah,
the most beneficent,
the most mercifull
==========================
system information:
vendor : $( getprop ro.product.brand )
model : $( getprop ro.product.model )
ROM : $( getprop ro.build.display.id )

running the script...
start at:
$( date +"%m-%d-%Y %H:%M:%S" )
==========================" | tee -a $LOG_FILE;

# unmount sdext if mounted
umount /system/sd

# fix sdcard speed
if [ -e /sys/devices/virtual/bdi/179:0/read_ahead_kb ]; then
echo "2048" > /sys/devices/virtual/bdi/179:0/read_ahead_kb;
echo "fix sdcard speed tweak [OK]" | tee -a $LOG_FILE;
fi;

# create sdext dir in /system
if [ ! -e /system/sd ]; then
echo "WARNING!: no sdext dir
please create dir /system/sd" | tee -a $LOG_FILE;
fi;

echo "SDEXT directory check [OK]" | tee -a $LOG_FILE;

# mount sdcard all type
#busybox mount -o noatime,nodiratime,nosuid,nodev /dev/block/mmcblk0p2 /system/sd;
#mountext=`busybox mount | egrep 'ext2|ext3|ext4'`;
#if [ -n "$mountext" ]; then
#	chown 1000:1000 /system/sd;
#	chmod 771 /system/sd;
#fi;
mount -t rfs /dev/block/mmcblk0p2 /system/sd

echo "akuro: sd-ext mount [OK]" | tee -a $LOG_FILE;

# create the directories

if [ ! -e /system/sd/app ]; then
mkdir /system/sd/app;
busybox mv /data/app/* /system/sd/app;
fi;

if [ ! -e /system/sd/dalvik-cache ]; then
mkdir /system/sd/dalvik-cache;
busybox mv /data/dalvik-cache/* /system/sd/dalvik-cache;
fi;

echo "akuro: preparation step [OK]" | tee -a $LOG_FILE;

# mount sd to data directories
mount -o bind /system/sd/app /data/app;
chown 1000:1000 /system/sd/app;
chmod 771 /system/sd/app;

if [ -e /system/sd/app ]; then
echo "akuro: app mount step [OK]" | tee -a $LOG_FILE; else
echo "akuro: app mount step [FAIL]" | tee -a $LOG_FILE;
fi;

mount -o bind /system/sd/dalvik-cache /data/dalvik-cache;
chown 1000:1000 /system/sd/dalvik-cache;
chmod 771 /system/sd/dalvik-cache;

if [ -e /system/sd/dalvik-cache ]; then
echo "akuro: dalvik mount step [OK]" | tee -a $LOG_FILE; else
echo "akuro: dalvik mount step [FAIL]" | tee -a $LOG_FILE;
fi;

if [ -e /system/sd/data ]; then
mount -o bind /system/sd/data /data/data;
chown 1000:1000 /system/sd/data;
chmod 771 /system/sd/data;
fi;

if [ -e /system/sd/data ]; then
echo "akuro: data mount step [OK]" | tee -a $LOG_FILE; else
echo "akuro: data mount step [FAIL]" | tee -a $LOG_FILE;
fi;

sync;

# end
echo "==========================
done at:
$( date +"%m-%d-%Y %H:%M:%S" )
all praise is due to Allah
==========================
-- have a nice day --
kurotsugi@xda
==========================" | tee -a $LOG_FILE;

if it didn't work we'll need to figure out how to mount the rfs partition. busybox's mount didn't support rfs yet. in this script we're trying to use samsung's binary file.

btw, I wonder how did you format your sdext to rfs?