I've got the problem in IE6 mostly sorted however there is a white space of 6px between the top banner area and my navMainWrapper underneath it. (in IE6 only)

I've tried a few things I found out from googling bug fixes but haven't come accross anything that works yet.

Also still cant figure out why there is a 20px space between my left column and the middle column in IE6&7 while in FF and IE8 its only 5px.
More than likely they are being caused by Box Model interpretation differences between the browsers.