Web app interfaced with Facebook not working for one person

I have a web app, which runs locally, to interface with Facebook. That is, my app would write to the current user's Facebook wall. It worked for me using Firefox 3.6 and Chrome 10, but I have one test user who said it didn't work for him, and he didn't even get to the [Allow] and [Not Allow] screen, and yes, he was using Firefox as well. What could prevent Facebook from processing the request from an identical app (same code)?

开发者_运维知识库and would anyone want to give it a try?

Are you using popups to show the "[Allow] [Not allow] screen"? May be your test user "just" forget to enable the popups on facebook domain. The problem is, my clients experience that, 90% of visitors not allow popups, so the auth process just stops, and no error message has been generated.