Can someone explain this behavior with the border line? easytabs plugin

Can someone explain this behavior with the border line? easytabs plugin

I've been trying to manipulate the jquery easytabs plugin, and ran into something that stumps me (not too hard, I'm not a CSS expert and I suspect it is a CSS related issue, but maybe not).

Here are two simple pages.

http://www.squeezypork.com/demo1.html
http://www.squeezypork.com/demo2.html

In Demo 1, the tab outline works in the way  I want it to work - it vanishes under the text and follow the tab around.

In Demo2, the tab outline doesn't work right, and appears under the tabs.

Any idea what is going on here? The only difference in the HTML is the H2 tag, which was removed in Demo 2 and replaced with a text tag (P).

Oh, I have to mention it only does this in FIREFOX browsers. IE renders ok no matter what page you look at, which seems to indicate to me a browser issue (of course).

Any help?

My apologies in advance if this question is in the wrong spot. I looked, this seemed to be right.