why does chromeless popup go full screen?

Hi,

I have a problem with a chromeless popup window that always wants to go full screen. It initially opens at the right size, then goes full screen (you can see 'close' button jump across the top title bar).

I've uploaded the pages here http://www.architecturemix.com/home.html If you click on the top photo button (this is a test page, so it's the only one that 'works' at the moment), you'll see the problem.

I'm using this actionscript on the button:

on (release) {
getURL("javascript: openIT('Cartier_movie_popup.html',550,400,null,null,'mywinname01')");
}


The javascript in the main HTML page is this:

<script language="javascript" type="text/javascript" src="chromeless.js"></script>
<script language="javascript">
function openIT(u,W,H,X,Y,n) {
var cD ='close_down.png'
var cU ='close_up.png'
var cO ='close_over.png'
var cL
var tH ='<font face=verdana size=2 color=#FFFFFF >ArchitectureMix</font>'
var tW ='ArchitectureMix'
var wB ='#3399FF'
var wBs ='#000062'
var wBG ='#000062'
var wBGs='#00FF00'
var wNS ='toolbar=0,location=0,directories=0,status=0,menu
bar=0,scrollbars=0,resizable=0'
var fSO ='scrolling=no noresize'
chromeless(u,n,W,H,X,Y,cD,cU,cO,cL,tH,tW,wB,wBs,wB
G,wBGs,wNS,fSO)
}
</script>

I've asked the same question on actionscript forums, but people think it's a javascript problem. What is overriding my settings?

TIA
NoBob