this one is simple andy.
open your html file bannerframe.htm and look for the following source...
"<img src="images/banner10.jpg" width="586" height="50" align="absmiddle">"
change it to the following and you should be fine...
"<center><img src="images/banner10.jpg" width="586" height="50></center>"
I think dreamweaver added the "absmiddle" tag. this is a rubbish attrib of the <img> tag.
if you get the chance and are into learning HTML properly, get rid of dreamweaver (its rubbish, and produces poor code) and spend the time with a good HTML book/internet resource to learn howto code.
you will be surprised how easy it is to pickup. I do ASP/HTML websites/applications for a living and NEVER use dreamweaver..... I personally use Homesite.
hope that helps.... ive finished my rant!