Just a few friendly suggestions:
You might want to edit the left nav css with this:
.navigation { text-align:left;
padding: 5px;
text-transform: uppercase;
height: 100% }
.navigation a,.navigation a:hover { color: #000000; font-family: Helvetica, Geneva, Arial, SunSans-Regular, sans-serif; background-color: #7AB0D2; display: block; margin: 2px 0; padding: 4px }
.navigation a:hover { color: white; font-family: Helvetica, Geneva, Arial, SunSans-Regular, sans-serif; text-decoration: none; background-color: #005E9B; margin: 2px 0; padding: 4px }
Your main sections padding is nonexistant in FF (works in IE though)
You might want to include borders for the images in the content on the homepage.
You might want to look at some of your CSS image paths (they still have file:// in them from your HDD)
You might want to optimize the image in the who is in holland mouseover effect.