I recently upgraded my wordpress installation to 2.3 and move the whole lot to a new domain and host. Before the the site was valid XHTML 1.0 transitional but now it appears not. I have added a few plugins since the move.
Details can be found here
Also the CSS has always had an error which I would like to resolve, details here
I'm pretty new to PHP and web dev and would like a little advice on how to clear up these errors, mainly the XHTML ones.