I'm unsure. I like the idea of the left nav but it does seem to steal a lot of screen space from the
content. Maybe making it a little narrower would help, or if possible have it as a slide in/ out?
It is a little bright too - Going a little more "hint of" in the would help that immensely without actually taking anything noticeable away from the contrast I reckon.
I'm not big on the grey, but can live with it. However the buttons now seem somewhat wrong for the theme!
As the Pnphp logo is merely a link to the board index and there's already that top and bottom of the page it might as well be ditched. It certainly clashes with everything and there's probably no point changing it for something else when it can just be gone.
I think overall I do prefer it to the blue though, it's just not quite as polished as it maybe could be

It's just that little too harsh after a long day, and a little too cramped for a 1024x768 screen.