I tested this on 7.5.6 and 7.5.8.
when posting using html.
Using say a iframe.
HTML
<center><iframe width="640" height="360" src="//www.youtube.com/embed/FzqQskGoURE?rel=0" frameborder="0" allowfullscreen></iframe>
the drop down menu tabs when viewing a topic such as:
Topic Options, Manage Topic and Rate this Topic.
appears behind the iframe.
So you either can't select all the options or rate the topic.
Unless you add lot of white space above the iframe.

Also:
Using the media tag button it appears okay as long as you don't use the full url(meaning the tag number only not www.Bla bla.
Not sure why on that part.

Did I miss a old post on this somewhere?
I thought that the regex would have been updated for this new version.

Blue Man Group
There is no such thing as stupid questions. Just stupid answers