IE pop-up

Ok, have a real serious problem here. Any time a customer goes to the site to view it in internet explorer, they are getting a pop-up that says: "This page contains both secure and nonsecure items. Do you want to display the nonsecure items?"

I've gone through most of the code and tried my best to switch as many links as I could from external to internal. No luck, I am still getting this annoying popup. Any ideas on what I can do so that my customers aren't turned away from it?

Also, in firefox, I have the lock image, but there is a cross through it?

Ok, have a real serious problem here.
But you have to guess at what it looks like...

Post a url so that all can see the problem in action

Good point. The website is:

http://www.praiseandplay.com/catalog

Problems highlighted:

Man, you guys make it look too easy. :D Wow. IT WORKED. Thank you, thank you, thank you.