You are trying to open jwplayer in a FancyBox lightbox overlay? And you don't need anything else to show in FancyBox?
Then start by going to the FancyBox options under Settings > Media > FancyBox and unable it for all media. FancyBox will not work anymore at this point but we'll come back to that later.
Then, try to get your jwplayer working outside FancyBox. Meaning: how would you normally include a movie in jwplayer on your site? Or can you make it play the movie via a direct link?
For example, you currently try to show http://miami-immigrationattorney.com/wp-content/themes/pozogoldshtein/jwplayer/video.html?iframe inside an iframe in FancyBox. This might be a good idea but you need to know if the player via that URL works when opened directly. Follow the link and see... To me it does seem to work but maybe you need to change some parameters like http://miami-immigrationattorney.com/wp-content/themes/pozogoldshtein/jwplayer/video.html?id=mediaplayer&file=playlist.xml&plugins=http%3A%2F%2Flp.longtailvideo.com%2F5%2Fflow%2Fflow-2.swf&flow.pluginmode=HYBRID&controlbar.position=over
If you've got it working outside FancyBox like that, you can then go back Settings > Media and enable the iFrame feature for FancyBox and control its size and options there. Then link from your site to that working URL with
class="fancybox-iframe" (like you already have done).
Alternatively, you might embed any content in jwplayer with custom code directly in your page/sidebar content. If you have a working embedded player, you can then wrap that code inside a div with a unique ID (or example
id="my_video_1") and that wrap that div again in another div with
class="fancybox-hidden" to hide it from view.
Then go back to Settings > Media and enable the feature Inline content for FancyBox (same as normal images, you can remove any extension like jpg png gif from the auto-detection box) and link to that content with