[Lynne]

Here are a couple of things I see right off the bat. Again, I strongly urge you to get some sort of web developer toolbar if you are going to chase classes/styling on a site:
- the css for the div your posts are in is not written int he same way the others are written.
example

.header_middle {-moz-background-clip:border;-moz-background-inline-policy:continuous;-moz-background-origin:padding;background:transparent url(http://www.farfosh.com/style/images/side_edges.png) repeat-y scroll center top;height:181px;padding-left:14px;padding-right:14px;}

You don't have anything like that written for your posts div. Each of those other divs also has similar styling for the divs within, but you have nothing like that for your posts divs.

- in your posts div, you have another div in there where the width is set to 100%. Your other divs are set to 978px. That is what pushes it out.