I have tried to use the coding directions, cleared my cache and for days I have been trying to get rid of the black box around the videos without success.  JoomlaWorks offers the worst extensions I have ever seen and I would not suggest anyone use them unless of course you have time to burn.

I'd like to add that I typically don't have issues like this, so to build extensions that are ugly and need to be modified is insane.  I hope people know what they are getting themselves into when they attempt to use this companies extensions.  This is my third and every one a disaster to work with.

You need to do the MVC template thing to customise the design, and thus get rid of the black box:

www.joomlaworks.net/extensions/free-premium/allvideos

So you can either choose to use the versatile base styling of the plugin or simply override it (both the HTML and CSS code) by copying the plugin's folder /plugins/content/jw_allvideos/tmpl/Classic in Joomla! 1.5 or the folder /plugins/content/jw_allvideos/jw_allvideos/tmpl/Classic in Joomla! 1.6 or newer TO your Joomla! template's /templates/YOURJOOMLATEMPLATE/html/jw_allvideos/ folder (create it if it doesn't exist), as you would with components and modules.

and then edit the margin/padding in CSS file you've moved. Simples.