Yes, that’s an annoying one – and it has less to do with your Theme’s CSS and more to do with teh Flash Player.
Easy remidy is at hand, even though it means that you need to add code to each video.
Here’s how you do it:
Your videos will be embedded with both <OBJECT> and <EMBED> tags to make Internet Explorer and Firefox happy at the same time. You need to amend the following statement in the <OBJECT></OBJECT> tags:
<param value="transparent" name="wmode"></param>
You also need to put the following attribute into your <EMBED> statement:
wmode="transparent"
Happy Days 😉