Internet Explorer, Flash, WordPress conflict?

I am开发者_运维百科 currently building a portfolio site here... http://2x2design.co.uk/

It has a subtle flash header animation which seems to be working fine in all but Explorer where it causes all sorts of problems, particularly when you are scrolling across the page.

I need to identify what part of the code on that page is causing the problem. I know it is not the swf as I have tried substituting that with other swf's from sites which work fine in IE and the same problem occurs. The site is running from wordpress, it has a few plugins enabled and the doctype is XHTML+RDFa 1.0 for use with facebook social plugins.

Any help would be appreciated.

It is probably because of the transparent background. But like I said, I think the best thing would be to replace it with an image on older browser.