Networking with XP

I've been using an Airport Express network for about four months now and haven't had any problems whatsoever, not even a single reset. I connect to my PC desktop every now and then to transfer files which is easy enough but recently this method has partially stopped working. For some reason, every time I navigate to My Documents on the PC, it comes up with a blank window showing '0 items' down the bottom. Why is this so? I can't see how it's a problem with Panther because connecting to every other folder is a breeze! What can I do to overcome my conundrum?

Thanks for any advice.