Site works in IE8, FF, Chrome but shows "connection error" in IE7

My site is showing a "Internet Explorer cannot 开发者_Python百科display the webpage" error in the browser when I visit it in IE7 but every other browser is fine.

I have tried from multiple machines and it works fine in IE8 Compatibility mode.

When I visit it in FF, the error console shows.

Error: Permission denied for <http://ad.uk.doubleclick.net> to call method Location.toString on <http://www.MYDOMAIN.com>.

I am not sure if this is related??? I am positive this is not a browser setting error as it is on any IE7.

Thanks Chris

Looks like the doubleclick advertising is trying to do cross-domain scripting. Firefox is failing gracefully (and so is IE8, probably), whereas IE7 is giving up.