penders - 9:29 am on Nov 10, 2011 (gmt 0)
And yes it's actually a slideshow in an iframe. But even if the background default of the frame is white, why doesn't it show in Firefox as white? I but the background color as blue in CSS but that doesn't help either.
Providing the background of the framed document is left as the default (white), other browsers appear to treat the iframe as transparent, showing the background of the parent container/document. To make IE do the same I believe you need to set allowTransparency="true" on the iframe itself. Although this is a non-standard attribute it appears to work cross browser.