Have you resolved this yet?
Have you seen this page:
Using the IE8 X-UA Compatibility Meta Tag Properly
http://acidmartin.wordpress.com/2009/03/21/using-the-ie8-x-ua-compatibility-meta-tag/
He claims that adding a meta tag to the file will modify the rendering behavior
but points out several important rules for successful usage. Assuming he is correct, then perhaps you could inject the met tag into the HTML stream.