css link styles don't function from a mapped network drive

I'm redesigning a website at work and I've found that because the html files reside on a mapped network drive the css styles for links don't work. With the files on the network drive the links act as if there are no styles for links, but if I move the file to my computer then Firefox and IE display everything correctly. This problem only occurs for the a:link, a:visited, a:hover, & a:active styles, all the other styles display correctly.

The easy solution is to move the folder to my computer, but the networked folder get's backed up every night which is why I would prefer to leave it where it is. Does anyone know of a reason why the css links don't function from a networked drive or how to fix it?