Comment 3 for bug 135886

I added the package pm-utils, too. A possible workaround or true bugfix would be to integrate the following script in pm-utils (found it here: http://forum.ubuntuusers.de/topic/136999/):

#!/bin/bash

get_env_var_of_process() {
  local pid="$1" envvar="$2"

  cat /proc/$pid/environ | tr '\0' '\n' | sed -ne 's/^'"$envvar"'=\(.*\)$/\1/p'
}

send_dbus_msg_to_pidgin() {
  local msg="$1"

  for pid in `pidof pidgin`; do
    user=$(get_env_var_of_process $pid USER)
    session_bus_address=$(get_env_var_of_process $pid DBUS_SESSION_BUS_ADDRESS)
    DBUS_SESSION_BUS_ADDRESS="$session_bus_address" su "$user" -c "purple-remote $msg" | logger
  done
}

case "$1" in
  hibernate|suspend)
    logger "Setting Pidgin offline..."
    send_dbus_msg_to_pidgin "setstatus\?status=offline" | logger
    ;;

  thaw|resume)
    logger "Reanimating Piding..."
    send_dbus_msg_to_pidgin "setstatus\?status=available" | logger
    ;;

  *)
    send_dbus_msg_to_pidgin "jabber:getinfo\?screenname=foosel\@via.im" | logger
    ;;

esac

exit $?

Just create it in /etc/pm and add some symbolic links in /etc/pm/sleep.d and /etc/pm/power.d, don't forget to chmod +x it ;)