Re: Transparent background
OK Cool, so the first thing that I would try is in the following line....
<embed id="viewer" width="100%" height="100%" flashvars="preloaderColor=0xffffff&xmlDataPath=gallery.xml" wmode="transparent" quality="high" bgcolor="#1c2c45" name="viewer" src="viewer.swf" type="application/x-shockwave-flash"/>
you have bgcolor="#1c2c45"
I'd drop that whole bgcolor statement all together. and see how that goes.
I have IE 7.0 and Mozilla Firefox 18.104.22.168 and it display's nicely in Firefox, but as you say in Exploder is doesn't.
The other thing that I have started doing on websites that I develop is putting the spread firefox image down the bottom of all my pages and a little comment saying this site is best viewed with Firefox. i have found so many stupid little quirks in IE rendering that mostly I have just given up. I develop for Firefox, try and fix for IE.
Sites where I have the Galleries working transparently are:
Nice Fish website by the way looks good and smooth, loads quickly and seems easy to navigate.
PS. If this doesn't fix it let me know and we can have another crack at it. :)