Pues hace unas semanas contesté a un mensaje parecido, y hice éste código para rotar banners "SWF":
<?
srand((double)microtime()*100000000);
$total = "3"; //cantidad de banners que se rotarán
$numero = rand(1,$total);
$banner = array();
$height = array();
$width = array();
$tipo[1] = "swf";
$banner[1] = "banner1.swf";
$height[1] = "68";
$width[1] = "450";
$tipo[2] = "swf";
$banner[2] = "banner2.swf";
$height[2] = "68";
$width[2] = "450";
$tipo[3] = "swf";
$banner[3] = "banner3.swf";
$height[3] = "68";
$width[3] = "450";
echo "<param name=movie value='$banner[$numero]'>";
echo "<embed src='$banner[$numero]' type='application/x-shockwave-flash' width='$width[$numero]' height='$height[$numero]'>";
echo "</embed>";
?>
Espero te sea útil y para cualquier cosa, acá la resolvemos
