I think the template is there, but the CSS is not.
Here's where it's looking for the CSS files (and apparently not finding them):
<link href="manager/templates/avon/css/styles.css" rel="stylesheet" type="text/css" />
<link href="manager/templates/avon/css/reset.css" rel="stylesheet" type="text/css" />
<link href="manager/templates/avon/css/text.css" rel="stylesheet" type="text/css" />
<link href="manager/templates/avon/menu/menu_style.css" rel="stylesheet" type="text/css" />
The files are there, but if you inspect them (using the Web Developer extension for Firefox) you see that all these files are complete HTML documents, not CSS files - obviously something is really wrong with that.
That's whats puzzling me. The css files are present and correct and the same template is used for all the inside pages and they're all displaying as they should.
The puzzling aspect is that for some reason the product catalog page is only showing the HTML and is not linking to the css files for some reason. The only difference between this page and the other inside pages of the site which use the template is that the product catalog page is a parent node for other pages.