If you're not getting new posts in a group where you know the group should be getting posts, then most likely your news client has a corrupt file. Unsubscribing and resubscribing from the group will generally fix the problem. If that doesn't work then you may need to reset the group.

Outlook Express
Open Outlook Express, right click on the group having a problem. Select properties, then local file, then reset. After the group has been reset download the headers again by clicking on tools, "Get Next XXX headers" where the XXX is the number set in tools, options, under the read tab. The effect will be the same as if you had just subscribed to the group.

Netscape
Click on Start in the Windows start bar, then find, files and folders. Set the search to look in c: and for files named "*.snm" (don't include the quotes). In the list that is returned right click on the group with the problem and select delete. The effect will be the same as if you had just subscribed to the group.

If resetting the group has not solved the problem, please use the following form to report the problem to the newsgroup administrators -
Problem reporting form