I like the layout - same I alwasy use and the most common: header, footer, left, right.
I think you could use a stronger demarcation between your left and right column and the middle content. That would help the custoemr keep his or her attention focused on the element they were looking at. Just make the line a pixles or two thicker and slightly darker.
I think your header could be thinner no need to have it much larger than about 70 pixels high, and that's only if you're going to put a benner in it. When a user hit;s your page, you want them to see as much product as possible. The thinner the header and the more products and product information that shows without scrolling, the better.
Ditto for footer. Not as much of an impact, but it's making the page unecessarily long. I thnk you could cut/edit the following lines:
cut:latest technoligies (you rcustoemrs don't care)
edit: I didn't know the contact us was a link until I rolled over it.
cut: best viewed: 100% percent of your visitors are using the browser they like and 98% of the time it's already going to be IE or NetsCRAP
edit: combine the copyright and company info lines into one line.
Last few concerns:
For your products, the links are underlined.
For your nav, the TD/link is highlighted on rolled
For footer links, link text is highlighted.
I suggest you go with all your non navigation links being underlined, otherwise people might not know they are link.
The graphic on lower rght is too washed out. IMO
SEO concern: suggest you put at least some description on each product, even if it's only the first 50 words of the real description; it will give you more and varied content for the spiders to feast on. Right now, you most dense keywords are (those words that occur the most often):
item available
show details
put title tag on your show details link (View Details on XXXXX)
Well Done!