The CMS you are using has a nice theme indeed I would try to place an image in the header though. It's too sad without one. Anyway .. the site is nice. Best of luck with it and keep us posted on the development.
I would personally make the header a bit busy and with a company slogan or more of a "Tag Line" This brands YOU.
* New colour scheme looks Really Good!
A Few more reccomended tweaksThis may seem like a lot of work but in the end, its the results that matter!)
* Remove the nav menu on the left and just keep all the links on the header.
* Instead of the nav menu, place the login form. These are always kept on the left unless some tech. restriction or something.
* Also try to show the Ad Sense Ads on the left side( New survey shows ad sense revenue to be 37% better when displayed on the left, 69% better if on the top of the page - compared to ads on the right...that too at the bottom!...so)
* For your header you can also place the domain search box as the header space is quite roomy.