Preg_replace werkt niet goed

<?php
$smileys=array(
'#:D#' => '<img src="../images/smileys/grin.gif" alt="Grijns">',
'#:alien:#' => '<img src="../images/smileys/alien.gif" alt="Alien">',
'#:angel:#' => '<img src="../images/smileys/angel.gif" alt="Angel">',
'#:ballon:#' => '<img src="../images/smileys/balloon.gif" alt="Ballon">',
'#:ban:#' => '<img src="../images/smileys/ban.gif" alt="Ban">',
'#:batman:#' => '<img src="../images/smileys/batman.gif" alt="Batman">',
'#:=#' => '<img src="../images/smileys/clap.gif" alt="Klappen">',
'#:klappen:#' => '<img src="../images/smileys/clap.gif" alt="Klappen">',
'#:cowboy:#' => '<img src="../images/smileys/cowboy.gif" alt="Cowboy">',
'#:alien:#' => '<img src="../images/smileys/alien.gif" alt="Alien">',
'#:666:#' => '<img src="../images/smileys/devil.gif" alt="Duiveltje">',
'#:duivel:#' => '<img src="../images/smileys/devil.gif" alt="Duiveltje">',
'#:...:#' => '<img src="../images/smileys/dots.gif" alt="...">',
'#:o#' => '<img src="../images/smileys/eek.gif" alt=":o">',
'#:eek:#' => '<img src="../images/smileys/eek.gif" alt=":o">',
'#:fuck:#' => '<img src="../images/smileys/fuck.jpg" alt="Fuck">',
'#:alien:#' => '<img src="../images/smileys/alien.gif" alt="Alien">',
'#:guns:#' => '<img src="../images/smileys/guns.gif" alt="Guns">'
);
$_GET["text"]=preg_replace(array_keys($smileys), array_values($smileys), $_GET["text"]);
?>

Het probleem: als $_GET["text"] #:D bevat, word er niets meer weergeven na #:D.
(#:D is ook niet zichtbaar).
Hoe kan ik dit probleem oplossen ?