I found a wired problem in our user's firefox. in our project, we need load many javascript files to render the form, we have two similar js files, in firefox one loaded successfully while the other will not, but both of the js files can be loaded successfully in Chrome. I debugged in firebug, in most times, it will have no return, and if I try to refresh the page, I can still see the request of previous page, and the response says "please reload the page to get source for http://......" we doubt if this is because the server didn't return successfully, I used WireShark to monitor the packages received from server. It is strange that the js file returned with Http code "200" it means the server returned successfully, but the browser didn't load it. and this problem only happens in firefox of our user in north china, for those from Japan, Thailand, USA don't have this problem, and if I use proxy in USA, the problem will not happen either.