We have a CMS system whose web interface gets served over HTTPS. This works beautifully for Firefox, but when we load it in IE6 or IE7, it complains that \"This page contain
If you can't see anything that isn't using SSL, then this is usually down to a broken SSL certificate somewhere. I don't know of anything off-hand that will tell you what exactly what the problem is, but you can get a list of everything that's loaded easily enough.
The media tab on Firefox's 'page info' dialog (right click on the page) will do it, it might also be worth having a go with Fiddler (which is an excellent, and extremely useful piece of software).