Looks good. It's touching the very top of the browsing space, I prefer to see a little background there, but I am not sure about other people's opinions on that.
And, try and make the cursor change to the link cursor when the mouse hovers over the collapse / expand boxes on the right.
The fully justified text in some of the collapsIble parts creates very large spaces between words, I am not sure if many people care but if I wrote the text that would annoy me.
When the vertical scrollbar appears the site moves a little to the left due tot he centering, again, I'm not sure if anyone cares, but I would have used an outer div set to 90% and then centered the layout inside the outer div so that its still centered but doesn't budge sideways when the scrollbar appears.
Also, is that meant to be a web design site? because it only mentions "our services" on the welcome message. And if it is a web design site... try not to use table-built layouts, its hardly professional.
Another few small things, being a non-American site, I would advise using international English spelling (same as Brittish spelling) but it isn't important.
There is no favicon set, again it's not very important. The site isn't valid Xhtml, some people don't care about this, but a web services site should, http://validator.w3.org/check?uri=http%3A%2F%2Fwww.kernel-technology.com%2F
Dont worry about my various minor criticisms, overall it looks great.