i'm new here.. this forum helped me make exactly what i wanted. THNX! But i only work on a mac and everything shows perfectly in all my browsers (Opera, FF, Safari). I can't test anything in IE. Looking into iFrames, it said to add a - allowtransparency="true" property to your iFrame. Like this:
<iframe src="..." allowtransparency="true"></iframe>
Maybe it'll help IE show a transparent background...
let me know if it works.. can't test it myself ;)