Firefox blocking URLRequest

I’ve created a client that communicates with a server via XML-RPC through a network using the URLRequest object to contact the server.

When activating the client through flashplayer, explorer or chrome, the xml-rpc messages are sent. When using firefox, for some reason these xml messages are blocked, and are not seen on the server.

What’s causing firefox to block xml messages to a remote server and how can I make it work???