Is there a simple, upfront method to have FF and IE treat hidden JW Players the same?
I am placing different instances of the player dynamically in jQuery generated
If you're using JavaScript to change tabs, why are you hoping for a pure CSS/HTML solution for your problem?
I think you have to use JavaScript.
Take a look at the JW Player API: http://developer.longtailvideo.com/trac/wiki/Player5Api
You can call the stop() method on the player.
player.stop();