I see a problem. And from the html output it would appear that your left column is being stacked on top of the content because it is nested for some reason.
Umm… did you try adjusting the template to add the left column?
<div class="col-main" id="main">
<div class="col-left side-col">
I don’t think it’s supposed to work like that. In the demo store, there isn’t a left column on the main page, but if you go down into the catalog you can read the html source and find that the columns are not nested like yours seem to be.
So, what did you adjust? Or… is it an error in the theme for 1.3.0? I don’t bother playing with the prepared themes much. I start from the Blank theme and never seem to run across problems like this. Of course, I did run into a few errors in the blank theme for 1.3.0 that I had to repair.
Are you ready to dive into the template files and correct them? Find out why your divs are nested, fix that and you should be seeing much better results.
I would start with checking the template/page/2column-left.phtml and other template files in that folder - look at the div structures and be sure that the child html calls are in the right order.