The free servers article numbers have changed. Most news clients are smart enough to notice this automatically, but some will not. If you notice that no new headers are being download you should first try to force the header download by using your clients 'download all headers' instead of the normal 'update/check for new headers'. Download the entire group list again can also help. If that fails remove your news server profile completely and start over, preferably using a different name for the profile.