(marco en rojo las lineas a las que se refiere el error) el codigo completo es el siguiente:
<!doctype html public "-//W3C//DTD HTML 4.0 //EN">
<html>
<head>
<title>Title here!</title>
</head>
<body>
<?
// Últimos mensajes publicados en foros phpBB2.
// Creado por XeRGio
//
www.xergio.net
//
// Edita lo que viene a continuación. Cambia solo lo que hay entre comillas "":
$directorio = "http://www.mipagina.com/phpBB2"; //Carpeta donde esta situado el foro.
$mostrar = "10"; //Número de mensajes a mostrar.
$caracteres = "25"; //Caracteres que se mostrarán de cada línea.
// Lo que viene ahora no lo toques para nada!!! a no ser que sepas de qué va el tema...
include("$directorio/config.php");
$total="";
$conexion = mysql_connect("localhost","usuario","password");
mysql_select_db("nombre de la base de datos",$conexion);
$consulta = "SELECT * FROM ".$table_prefix."posts ORDER BY post_time DESC";
$result = mysql_query($consulta);
$i = 0;
while ($row = mysql_fetch_array($result)) {
if ($i <= $mostrar) {
$consulta1 = "select * from ".$table_prefix."forums where forum_id='$row[forum_id]'";
$resultado1 = mysql_query($consulta1);
$datosf = mysql_fetch_array($resultado1);
$consulta2 = "select * from ".$table_prefix."users where user_id='$row[poster_id]'";
$resultado2 = mysql_query($consulta2);
$datosu = mysql_fetch_array($resultado2);
$consulta3 = "select * from ".$table_prefix."topics where topic_id='$row[topic_id]'";
$resultado3 = mysql_query($consulta3);
$datost = mysql_fetch_array($resultado3);
$datost[topic_total] = $datost[topic_title];
if (strlen($datost[topic_title]) > $caracteres) {
$datost[topic_title] = substr($datost[topic_title],0,20)."...";
}
//Importante: no dar saltos de linea en la siguiente linea para que el javascript funcione correctamente
$total.=" <font size=\"1\" face=\"arial\"><a href=\"$directorio/viewtopic.php?t=$row[topic_id]\" title=\"$datost[topic_total]\"><font color=\"#000099\">$datost[topic_title]</font></a><br> En <a href=\"$directorio/viewforum.php?f=$datosf[forum_id]\"><font color=\"#000099\">$datosf[forum_name]</font></a><br> Por <b>$datosu[username]</b></font><hr noshade size=\"1\" color=\"#000000\" width=\"100\">";
$i++;
}
}
mysql_free_result($result);
mysql_close($conexion);
?>
<script language="JavaScript1.2">
/*
Cross browser Marquee II- © Dynamic Drive (
www.dynamicdrive.com)
For full source code, 100's more DHTML scripts, and TOS, visit
http://www.dynamicdrive.com
Credit MUST stay intact
*/
//Specify the marquee's width (in pixels)
var marqueewidth=125
//Specify the marquee's height
var marqueeheight=250
//Specify the marquee's marquee speed (larger is faster 1-10)
var marqueespeed=1
//Pause marquee onMousever (0=no. 1=yes)?
var pauseit=1
//Specify the marquee's content
//Keep all content on ONE line, and backslash any single quotations (ie: that\'s great):
var marqueecontent='<? echo $total; ?>'
////NO NEED TO EDIT BELOW THIS LINE////////////
marqueespeed=(document.all)? marqueespeed : Math.max(1, marqueespeed-1) //slow speed down by 1 for NS
var copyspeed=marqueespeed
var pausespeed=(pauseit==0)? copyspeed: 0
var iedom=document.all||document.getElementById
var actualheight=''
var cross_marquee, ns_marquee
function populate(){
if (iedom){
cross_marquee=document.getElementById? document.getElementById("iemarquee") : document.all.iemarquee
cross_marquee.style.top=marqueeheight+8
cross_marquee.innerHTML=marqueecontent
actualheight=cross_marquee.offsetHeight
}
else if (document.layers){
ns_marquee=document.ns_marquee.document.ns_marquee 2
ns_marquee.top=marqueeheight+8
ns_marquee.document.write(marqueecontent)
ns_marquee.document.close()
actualheight=ns_marquee.document.height
}
lefttime=setInterval("scrollmarquee()",40)
}
window.onload=populate
function scrollmarquee(){
if (iedom){
if (parseInt(cross_marquee.style.top)>(actualheight*(-1)+8))
cross_marquee.style.top=parseInt(cross_marquee.sty le.top)-copyspeed
else
cross_marquee.style.top=marqueeheight+8
}
else if (document.layers){
if (ns_marquee.top>(actualheight*(-1)+8))
ns_marquee.top-=copyspeed
else
ns_marquee.top=marqueeheight+8
}
}
if (iedom||document.layers){
with (document){
if (iedom){
write('<div style="position:relative;border-style:solid;border-color:#000000;border-width:1px;width:'+marqueewidth+';height:'+marqueeh eight+';overflow:hidden;background:#cccccc;" onMouseover="copyspeed=pausespeed" onMouseout="copyspeed=marqueespeed">')
write('<div id="iemarquee" style="position:absolute;left:0;top:0;width:100%;" >')
write('</div></div>')
}
else if (document.layers){
write('<ilayer width='+marqueewidth+' height='+marqueeheight+' name="ns_marquee">')
write('<layer name="ns_marquee2" width='+marqueewidth+' height='+marqueeheight+' left=0 top=0 onMouseover="copyspeed=pausespeed" onMouseout="copyspeed=marqueespeed"></layer>')
write('</ilayer>')
}
}
}
</script>
</body>
</html>
Eso me da el error que especifique en el post inicial !!! 
