Ran into an issue with IE8 showing the following prompt with every page view under SSL.
Security Warning
Do you want to view only the webpage content that was delivered securely?
This webpage contains content that will not be delivered using a secure HTTPS
connection, which could compromise the security of the entire webpage.
Turns out the addition of the Microsoft AJAX CDN service is the cause in this particular case. Changing the script link to use SSL resolves the issue.