I\'m noticing this issue. I made a quick screen capture to demonstrate: http://dl.dropbox.com/u/904456/2010-06-14_2323.swf
Basically when you have a min-width set an
CSS:
body { width: 100% }
#main-wrapper { width: 100%; background-color: #000 }
#header-wrapper { width: 100%; background-color: #111 }
#header { width: 200px; margin: 0 auto }
#content-wrapper { width: 100%; background-color: #222 }
#content { width: 200px; margin: 0 auto }
#footer-wrapper { width: 100%; background-color: #333 }
#footer { width: 200px; margin: 0 auto }
The same concept can be applied for background images, though to maintain the appropriate effect (unless it is a pattern that can be repeated) you would need to have a very wide image or atleast one that fades to some background color. What you would do is place the image as the background image and then simply position it as center top and it will expand with the page.
Hope this helps.