well...a lot of your errors cascade.... you have some other things that are throwing stuff off. If you could get rid of those problems, you could see whats really going on.
like on line 107 in the validator view of your source...you have an open <p> that doean't close
There looks like other mismatches happening....
I had a couple plugins that wouldn't play nice...dropping strange <p> tags, and other things that wouldn't validate.
Here a cool solution I use that totally validates my site:
Just download the Clean The Content Function file.
It has two things in it, one is a bit of code to go into functions.php, and the other is a file you just place in your theme. Check into it a bit....it helps me a lot!