salve gente!
sapreste darmi una mano a risolvere questo problema di crossbrowsing?
perchè con firefox si visualizza perfettamente...con explorer non mi permette di vedere il background. essenzialmente il problema è lì!

codice:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//IT" "http://www.w3.org/TR/html4/frameset.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Title</title>
</head>
<body>


<style type="text/css">
html,body{margin:0;padding:0}
body{background: #666666 url(graphic/backcenter.jpg) repeat-y center;font:100.00% arial,sans-serif;text-align:center}
div#container{width:700px;margin: 0 auto}
</style>



<center>
<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=7,0,0,0" width="465" height="128" id="header" align="middle">
<param name="allowScriptAccess" value="sameDomain" />
<param name="movie" value="header.swf" />
<param name="quality" value="high" />
<param name="bgcolor" value="#000000" />
<embed src="header.swf" quality="high" bgcolor="#000000" width="460" height="128" name="header" align="middle" allowScriptAccess="sameDomain" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" />
</object>
</center>

<iframe id="center" name="center" src="center.html" width="450" height="320" frameborder="no">
  

Title</p>
</iframe>

<center>
<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=7,0,0,0" width="440" height="128" id="brands" align="middle">
<param name="allowScriptAccess" value="sameDomain" />
<param name="movie" value="levTextSpace.swf" />
<param name="quality" value="high" />
<param name="bgcolor" value="#000000" />
<embed src="levTextSpace.swf" quality="high" bgcolor="#000000" width="440" height="128" name="brands" align="middle" allowScriptAccess="sameDomain" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" />
</object>
</center>



</html>
grazie in anticipo!