lucy24 - 12:40 am on Nov 1, 2012 (gmt 0)
Never mind where the files are physically located. Is the URL of the html file (what you see in your browser's address bar) the same as the html's "real" location?
For live sites it is always safer to use site-absolute links beginning in / (slash = top level of your domain). It makes local testing a little trickier, because you'll have to run it through a pseudo-server like MAMP or WAMP. But that's not hard.