Is probably what you wanted to link to. Paths from CSS files are relative to the location of the CSS, NOT the HTML... that's why usually I don't put the common css into a subdirectory, and if I do the images called by the css go in css/images instead of /images... which can be handy anyways for separating presentational images out from content ones.
That said, you've got a disastrously broken layout here from all the dynamic fonts inside PX metric containers. I'm a large fonts/120dpi user -- the type of person %/em fonts are for; but because you've got so many fixed widths declared in PX pretty much everything is broken to the point of stuff looking 'slapped on the page any old way'... like are those near-invisible menu items supposed to be on the dark bar background? If so why isn't that bar on the menu instead of a separate element?
-- edit -- here's a screencap to show you what I mean by broken.