LinuxQuestions.org - Write special unicode chars in hardstatus of GNU Screen

Hi,
I want write the next specials chars to hardstatus of GNU Screen: "↑" (up arrow) and "↓" (down arrow), but it shows strange chars. How can I do this?
This worked to me before but I have to reinstall my SO (Ubuntu 11.04) and now it doesn't work.
Thanks in advance.
Regards.

ADD:
Config files

Code:

  $ cat ~/.screenrc

deflogin off

shell bash



termcapinfo xterm* ti@:te@

backtick 25 1 1 $HOME/bin/scripts_screen/velocidad_eth1

backtick 26 300 300 $HOME/bin/scripts_screen/espacio_libre_servidor

backtick 27 300 300 $HOME/bin/scripts_screen/espacio_libre_menor_que

hardstatus alwayslastline "  %{= Wb}%LD %d %LM, %c %{=b Wk}| %?%{=b rg}%27`%:%{= Wm}%?Espacio libre: %26` %{=b Wk}| %{= Wk}%25`"

Code:

  $ cat $HOME/bin/scripts_screen/velocidad_eth1

#!/bin/sh

bajada=`ifstat -qwni eth1 0.1 1 | tail -n 1 | awk '{print $1}'`

subida=`ifstat -qwni eth1 0.1 1 | tail -n 1 | awk '{print $2}'`

echo "↓ $bajada / ↑ $subida"

I think this problem is related to enconding but my locales are correct:

Code:

LANG=es_ES.UTF-8

LANGUAGE=es_ES:en

LC_CTYPE="es_ES.UTF-8"

LC_NUMERIC="es_ES.UTF-8"

LC_TIME="es_ES.UTF-8"

LC_COLLATE=C

LC_MONETARY="es_ES.UTF-8"

LC_MESSAGES=POSIX

LC_PAPER="es_ES.UTF-8"

LC_NAME="es_ES.UTF-8"

LC_ADDRESS="es_ES.UTF-8"

LC_TELEPHONE="es_ES.UTF-8"

LC_MEASUREMENT="es_ES.UTF-8"

LC_IDENTIFICATION="es_ES.UTF-8"

LC_ALL=

This is a capture of a screen session:
http://i.stack.imgur.com/8icXQ.png

You can see that the unicode characters in terminal are correct but not the unicode chars of hardstatus/caption screen.