Positioning of a second sidebar

Hi,
The website I’m trying to add a second sidebar to is
I’m looking to add a second sidebar on the right hand side to contain a few extra links that have been created. The theme is a modified version of the default theme included with wordpress.
I followed another post on here “creating a second sidebar” that was posted a couple of days ago to add the second sidebar by adding a php line to each of page, index, archive.php etc files. I then modified the CSS sheet to try and float it on left hand side and move the existing one to the right.
I have one problem…when page.php reads

<?php include(TEMPLATEPATH."/sidebar_left.php");?>
	<div id="content">....

I have both sidebars appear but the actual content does not appear, although this only happens on the home page and not on any other page.

When the code reads:

<div id="content">....</div>
        <?php include(TEMPLATEPATH."/sidebar_left.php");?>

Then the content appears but both sidebars appear on the right hand side, after the content regardless of how they are floated in the CSS.
As the existing website is live I’m trying to modify a local copy and then make the changes live so unfortunately there is no way to see what is happening.
If anyone can understand what I’m saying, trying to achieve and knows an answer then it would be greatly appreciated.
Thanks,