Loadclip() from secure source

I am using loadclip() to load several external images into my swf at runtime. However, I am getting an error with an image that is on an external secure server. The image is using https and the server my swf is loaded onto is using http. The image is located in the public domain on the Naval Oceanographic Office’s website, so I have no way to implement a cross-domain policy that I am aware of. I have tried AllowDomain(), but I may have not been using it right.

Here is my code:

var mcLoader:MovieClipLoader = new MovieClipLoader();
mcLoader.loaSystem.security.allowDomain()dClip(“”, picHolder);
function onLoadInit(mc:MovieClip) {
trace("onLoadInit: " + mc);

Any ideas or suggestions?