[jQuery] Before automatically closes tags...?

[DaveG]

I'm trying to enclose sections of the dom with a DIV tag. Basically I want all 
elements between headings (and including the top-most heading) enclosed in a 
DIV.

My approach is to scan through the DOM, find a header tag, insert an opening 
DIV tag, continue scanning until I hit the next header, close the prior div, 
and open a new div tag. Thus:
<h2>heading 2a<\h2>
...html tags...
<h3>heading 3a<\h3>
...html tags...
<h2>heading 2b<\h2>
...html tags...

Becomes (indent added for clarity only):
<div>
   <h2>heading 2a<\h2>
   ...html tags...
<\div>
<div>
   <h3>heading 3a<\h3>
   ...html tags...
</div>
<div>
   <h2>heading 2b<\h2>
   ...html tags...
</div>

I'm using .before to add the starting <div> tag, but it looks like .before 
automatically closes open tags. I don't see any mention of this in the docs. 
How would I go about adding an open ended tag to the DOM?

Alternately, is there a way of identifying each section between headers so I 
can .wrap with a div?

Here's the code snippet:
   var open = false;
   $('#text').children().each(function(i) {
      if( this.nodeName.match(/^H\d+$/) ) {
         if (open) {
            $(this).before('</div>');
         }
         $(this).before('<div class="xxx">');
         open = true;
      }
   });