Main menu questions - centering problems and styling

I have a totally new demo site and a main menu on the full size browser version that consist of one box per menu item and they are alignes horisontally. See demo site here: www.duosmart.se/enskede
Now the strange thing is that the menu won't be centered no matter how I play around with the settings.
Ay kind of suggestion that soves this totally weird issue would be highly appreciated.
Second: Is it possible to make all the boxed equal in width no matter of how many letters the link iten consist of?
It would look a lot better if tat was possible.
In Artisteer this was no brainer but here it's a bit more tricky. So please with sugar on top suggestions here as well?
All the best.