[Plugin: NextGEN Gallery] When Enabling Next-gen – secure site in IE displays security warnings

When I have the Nextgen gallery plugin enabled on my shopping site, when doing a shopping cart checkout, IE complains with a big security warning box. If Nextgen plugin is disabled, all works fine in IE.

This shopping site is at http://tinyurl.com/m4mn53 and when I am using IE8 and add a product to the shopping cart and then go to checkout, it gives someone the IE warning that says the following:

“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.”

If I disable this Nextgen gallery plugin, I don’t get this IE warning at all for Checkout. Can this be fixed without permanently disabling it?

Thanks,
CK