if you are using a .swf to call the .flv accross domains, security settings in the swf player may not allow it.
i love using download embedded, a Firefox extension, to download flash games and clips so i can open them in swiff player and a bunch of other players i have, but this only works on some of the files ...
Adobe wants Windows, Mac and Linux users to install a critical security update, issued Thursday, for Adobe's Flash Player. Without it, the company says, there are vulnerabilities in the program that ...