Segoe SemiBold not a common font
description
In a few places you're using "Segoe SemiBold" which is *not* a commonly installed font. "Segoe UI" is however, installed with Vista, 7 and various Office packages - I'm guessing "Segoe UI SemiBold" is what was meant.
It may be also be worth falling back onto Segoe WP as well for those looking at it on a phone.
ie:
h2 {
font-family: "Segoe UI SemiBold", "Segoe WP SemiBold", Segoe, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
}