I have a Flex file upload script that uses URLRequest to upload files to a server. I want to add support for http authentication (password protected directories on the serve
Seemingly similar problem was solved here. I urge you to also check the Flexcoders post linked to in the first post.
The problem was that FireFox uses a separate browser window instance to send the file upload request. The solution is to manually attach the session id to the request url. The session id is not attached as a regular GET variable, but with a semicolon (the reason for this syntax is unknown to me).