This appears to be a common issue on many ASUS laptops. Try this:

Source: http://thecodecentral.com/2011/01/18/fix-ubuntu-10-10-suspendhibernate-not-working-bug

Run this in a terminal:

gksu gedit /etc/pm/sleep.d/20_custom-ehci_hcd 

Copy and Paste the contents of the following into the text editor:

#!/bin/sh

#inspired by http://art.ubuntuforums.org/showpost.php?p=9744970&postcount=19

#...and http://thecodecentral.com/2011/01/18/fix-ubuntu-10-10-suspendhibernate-not-working-bug    

# tidied by tqzzaa :)



VERSION=1.1

DEV_LIST=/tmp/usb-dev-list

DRIVERS_DIR=/sys/bus/pci/drivers

DRIVERS="ehci xhci" # ehci_hcd, xhci_hcd

HEX="[[:xdigit:]]"

MAX_BIND_ATTEMPTS=2

BIND_WAIT=0.1



unbindDev() {

  echo -n > $DEV_LIST 2>/dev/null

  for driver in $DRIVERS; do

    DDIR=$DRIVERS_DIR/${driver}_hcd

    for dev in `ls $DDIR 2>/dev/null | egrep "^$HEX+:$HEX+:$HEX"`; do

      echo -n "$dev" > $DDIR/unbind

      echo "$driver $dev" >> $DEV_LIST

    done

  done

}



bindDev() {

  if [ -s $DEV_LIST ]; then

    while read driver dev; do

      DDIR=$DRIVERS_DIR/${driver}_hcd

      while [ $((MAX_BIND_ATTEMPTS)) -gt 0 ]; do

          echo -n "$dev" > $DDIR/bind

          if [ ! -L "$DDIR/$dev" ]; then

            sleep $BIND_WAIT

          else

            break

          fi

          MAX_BIND_ATTEMPTS=$((MAX_BIND_ATTEMPTS-1))

      done  

    done < $DEV_LIST

  fi

  rm $DEV_LIST 2>/dev/null

}



case "$1" in

  hibernate|suspend) unbindDev;;

  resume|thaw)       bindDev;;

esac

Save, then

sudo chmod 755 /etc/pm/sleep.d/20_custom-ehci_hcd