Does Facebook chat work for test users?

I have a project where part of the work is doing usability testing for an alternate interface to Facebook and this requires using the chat functionality for a specific test. I have created some test users and made them friends with each other. I am now testing by just logging in as two test users on Facebook.com on two separate browsers (Firefox 7 and Chrome 14.0.835.186) on the same machin开发者_开发问答e. Everything seems to work OK, but both of the users' chat windows indicate that no one is available to chat.

Is there some sort of permission I need to give to the test users when I create them for chat to work correctly? Or is there something that prevents this from happening (special for test users? being on the same machine?)

Any help would be appreciated.

It's a confirmed and assigned bug. See https://developers.facebook.com/bugs/317432454946419/