Margin/padding and background image positioning

You can look at the page located here: http://www.crhcf.org

I'm building a master page and content pages with Visual Studios. All of that is fine.

The problem I'm having is I have a 1 pixel wide vertical image of a gradient for the background and it is supposed to have a small shadow at the top because it starts just under the menu bar. If you look at the sidebar, you will see this shadow at the top of that graphic, but it stops when it gets to the section where I need it (main content section to the right of the sidebar). I can see the shadow on the actual 1px image, but it acts like the image in the page is getting scooted up, maybe behind the menu and hiding the top bar? I'm not really sure what's going on.

Also, I can't seem to get the padding to work for the main content section (where the word "foo" is at). I want a 20px margin/padding between it and the vertical line of the sidebar image. I've tried both padding-left and margin-left, but neither made a difference.