Your menu, as others have said, just isn't working. If I hover near the top of the item it appears to run away from the cursor and I'm left wondering, "They don't want me to click this?"
Ditch flash. Apple iPod, iPhone, iPad don't support it so customers won't be able to see your website (admittedly I didn't check if you have done a work around so correct me if I'm wrong).
The banner is moving quite quickly and causes me to simply blur my eyes and not focus on it which is the opposite of what you want it to do.
The portfolio on the home page is a good idea but I'm sure you can make it prettier! Maybe make the thumbnails bigger and zoom into the page rather than showing the whole page? i.e.
http://dvi.net.nz/portfolio/websites
The "Our services" panels could do with a bit more design flare. Also the quality of the jpg is poor, I can see the artifacts around the text. Better yet, ditch the images and just use CSS3 for the drop shadow on the text; but as a web design company you already new that
Your logo isn't standing out, it's hidden away. First and foremost your should portray your !!!BRAND!!! and then and calls to action. Make it more visible. Perhaps even putting it on the left and the menu on the right so the reading order starts with the logo. You will find the menu is not a problem as people always look for the menu on a website but they have no reason to look for a logo but you want them to recognise it!
The underline on the "Read More>>" link at the bottom of the page stands out too much. Maybe make it a lighter blue?
For your top navigation use an unordered list instead of lots of div elements. It's tidier and search engines are more likely to recognise that each menu item is part of a menu. Or you could simply apply your styling directly to your <a> elements there doesn't seem to be any obvious reason why there's all those wrapper divs. Just use display:inline-block on your <a> elements or display:block;float:left; inside a clearfix.
Give your ID's some more meaningful names. Instead of "container" use something that describes its purpose and hierarchy i.e. "content_container" and "header_container". This kind of structure will help with maintainability when someone else comes along, or you visit 6months down the track and forgot what the css class "#container" was for, etc.
Use an <H1> in your page. Currently you are starting with <H2>. Good SEO practise is to put your most relevant pitch into an <H1> element which the search engines will rank of high importance since generally <h1> is the page's most impacting title.
Give your images a fixed size where possible rather than letting the browser work it out for you. This will improve page rendering performance by allowing the browser to move past the image while the image is downloading. Otherwise it will have to stop and wait until it has downloaded the image to know how big it is and where to place the follow-on elements.
Some text in the images is too small and unreadable i.e. the bottom right images on
http://www.shawebdesign.com/seo.php - Not sure how this is helping your page. Seems like it is only there as a filler because the text didn't look as good at full width!
Text boxes on the contact page look like they are disabled. Make the background white or very light. Also the image here looks very generic and cheap. Again it's a filler but since you are a website design company you can't let clients think you are going to use cheap and generic images to build their website!
Logo design - Where's the portfolio?
Web develop - Where's the portfolio?
Web design - Where's the portfolio? (other than tiny images on the home page)
Well there's a few quick pointers to think about. Overall it looks ok but I think if you have a think about some of the things I point out above you could make this really shine!
Good luck; and sorry about all the 'constructive' comments! ;D