CSS Combine & Minify Problem

I am using Wordpress and W3 Total Cache plugin for Combining & Minifying CSS. This is because I don’t know how to Combine and inform WP where to look for the joined file.

My question is: The plugin no double combines some files (not all), yet in the page source I see the individual files loaded again. My site is:

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Initially I had 7 files. After combining I see 5 files including the combined file, most notably the heavy files.

What I want to ask is: is this procedure correct? Or is it I am thinking incorrectly? (Though similar thing happens with the javascript files too)

Any idea what I should do? I use Thesis as the theme.

To be frank (when am I ever not) minification of this sort is usually just used to cover up bad code. Bad code like having more than two CSS files per media target. Bad code like having 13k of markup AFTER minification for only 3.3k of plaintext, broken and nonsensical heading orders, 100k of javascript on a page that doesn’t appear to have ANYTHING that uses it, inlined presentation, tables for layout, non-semantic markup, IE conditionals for no good reason, classes on unique tags, etc, etc, etc…

Of course it’s wordpress, the code is gonna suck no matter what. Obfuscating the suck with minification is NOT the answer… Especially with 42k of minified CSS on a site layout that shouldnt’ need more than half that WITHOUT minification.