OOCSS is one of the silliest notions out there -- completely defeats the point of using CSS in the first place; might as well go back to HTML 3.2.
But play with it, you'll probably come to that conclusion on your own.
You missed cleaning up the href bloat
Actually, I'm referring to the tagline that should be part of the heading, the paragraphs for NOTHING inside the two div.footer, etc, etc...
Oh maybe the five H4's preceeding the first H1, and the multiple H1's? Open it up in FF, go into the web developer toolbar and hit "information -> document outline" you'll see three nice big [MISSING HEADING] in red?
Assuming that isn't broken in FF 3.6+ as well -- it's one of the two handiest bits of the web dev toolbar; the other being the "document size" tool that's broken in anything higher than 3.5.x.
For example, your first two paragraphs on the page I'd have as a H1 and a small tag, probably with a small inside the small where you're using a classed div....
<a href="http://xazure.net">Xazure</a><br />
a blog by <span>C</span>hristian <span>S</span>nodgrass<br />
about programming, web and game design, and everything else
The quintet of H4 would then easily be dropped to being H2 and the two h1's dropped to H2, the H2 dropped to H3... giving you a "proper" and non-broken heading order -- though I'd consider seeing if I could force it into a content FIRST layout and move the less relevant sidebar stuff after the main content area.
Though I've never been a big fan of the massive impersonal space wasting "WELCOME" headers... but that's me...
Otherwise all of those h4 should be h1 and that makes no sense at all unless you go for the HTML 5 thing and add a slew of pointless "section" or "article" tags to "reset the counter" on using them.
Basically you have:
H1 <font color='"red"'>[Missing Heading]</font>
H2 <font color='"red"'>[Missing Heading]</font>
H3 <font color='"red"'>[Missing Heading]</font>
H4 Recent News
H4 Recent Tips & Snippets
H4 Recent Project Posts
H4 Recent Recent Lessons
H4 EmpireAvenue - Pretty Neat
H1 Latest Posts
H2 Xazure Code Demo Plugin
H2 Three Column Layout with Divider without Images
H2 Changing WordPress Template with template_include
H2 HTML Lesson 1 – What is HTML?
H2 Lessons – Where to Start
H2 Columned Layout with Background and Divider without Images
H2 Adding a Code Box with Word Wrap
H2 Cloud Host Review – Rackspace Cloud
H2 A Few Site Tweaks
H2 Keep It Sorted: Binary Search Sort
Where I'd suggest trying to get that to the more "proper"
H1 Xazure a blog by Christian Snodgrass about programming, web and game design, and everything else
H2 Latest Posts
H3 Xazure Code Demo Plugin
H3 Three Column Layout with Divider without Images
H3 Changing WordPress Template with template_include
H3 HTML Lesson 1 – What is HTML?
H3 Lessons – Where to Start
H3 Columned Layout with Background and Divider without Images
H3 Adding a Code Box with Word Wrap
H3 Cloud Host Review – Rackspace Cloud
H3 A Few Site Tweaks
H3 Keep It Sorted: Binary Search Sort
H2 Recent News
H2 Recent Tips & Snippets
H2 Recent Project Posts
H2 Recent Recent Lessons
H2 EmpireAvenue - Pretty Neat
I'd probably also open it up semi fluid instead of suffering the 'crappy little stripe' syndrome -- which is really exacerbated by large fonts/120dpi. Also not sure what that broken thing on the side is supposed to accomplish...