It seems to work OK in Opera, except for the portfolio page. However, a commercial website should work in all common browsers and should never recommend one browser over another.
The design is very busy, to the point of confusion. My eyes didn't know what to look at first. Since you're advertising a design service, this isn't a good thing.
People expect to find navigation controls at the top or left. Having yours at the right is confusing, and there seems to be no compelling reason for it.
Similarly, I expected that clicking on the main display would send me somewhere, at least to a portfolio. The same with the white circles and headings beneath the display. (Especially since you use the circles on a navigation icon.)
The Twitter icon makes the page just a smidge too long; I have to scroll down to see the whole icon.
For some great advice on site design, have a look at
Web Pages That Suck -- especially the checklists.