I didn't notice that IE8 was any taller than other browsers.
2)My left and right .png arrows are pushed out by IE6 .... absolute positioning is not keeping it in place...
Your image is 900px wide but the container it sits in is only 860px wide.
Either change the container to 900px (and alter the arrow positions accordingly):
Or reduce the image to 860px width.
Once you start telling the browser to do things that are impossible then you will find that they may error handle in different ways
Ie6 will always stretch a container to contain its content but other browsers will let said content spill out and basically ignore it. That's why the arrows are different in IE6 because they are being placed from the bigger element.