ok lets see - bunch of additional html in your file that should have been created by the scroll plugin.
in you tabs.js file line(2) replace with this:
$(".jspPane > div").hide(); //Hide all content
then in your html file where you have the tabs delete the whole additional divs you created, so your new div has the structure
<div id="tab_content" class="jspScrollable">
<div id="tab1">your content</div>
that should do the trick - you might have to adjust your css a bit.