I wanted to share this in case it will help another.
I use Yahoo! Web Hosting and was developing a game for Facebook.
I was trying to host an HTML5 game that will be used inside the Facebook canvas. Facebook requires a secure server host. No problem. All went well except the Facebook site generated a "405 - Method Not Allowed" error. It s my understanding that Facebook makes a POST request to my URL and Yahoo doesn t allow this.
This was easily fixed by renaming the index.html prepared by C2 when exporting. Just rename it to index.php and everything goes great. (As I believe Yahoo uses PHP server tech.)
Hope that helps!