JWplayer with Wowza

I have a Wowza streaming engine server on our Intranet. I am using JWplayer to play the videos. There is no problem if the client has access to Internet, but if I disconnect from Internet, the JWplayer does not play. I found that if I use JWPlayer version 7.3.6 , and use Google Chrome on the client, it works. But FireFox, and IE does not work. Please help