Odd Ajax behavior with CDN

I’m having something strange happen when I launch a modal that contains an extension that publishes JS assets from a CDN. I found a way around it in most cases, but in one particular case I’ve hit a wall.

I’m using CloudFrontAssetManager so that I can use Amazon Cloudfront as my CDN. Everything works as expected with Ajax requests when I’m working locally and I’m not using a CDN. However, when I deploy to production and I’m using a CDN, I can see that my Ajax requests aren’t loading extension assets via POST.

I have a page that launches a modal with an extension that I developed for the JQuery Signature Pad (https://github.com/thomasjbradley/signature-pad/). Running locally, in Firebug I can see the assets in the console loaded via POST requests (6383

Screen Shot 2015-03-03 at 8.33.04 PM.png
). The widget displays without JS assets and throws an error. If the modal is closed and then open a second time, the widget displays properly.

Is this a bug or am I missing something? I’ve seen the issue discussed here but with no resolution - http://www.yiiframework.com/forum/index.php/topic/42019-problem-loading-extension-resources-from-external-cdn/. This is becoming a critical issue to the point that I might need to find a way around using a CDN.