[Tigga]

Ok, I looked over those files and both of them were modified correctly. Do you have phpMyAdmin where you could check to make sure the "isnews" column is there? I don't see a reason it wouldn't be if the installer ran correctly, but then again I don't really see a reason the news wouldn't be working. You could also try re-uploading your newreply & newthread files and then try making another news post.
If it's still not working, I could take a look at things for you if you would like to make a temporary account on your forums and give me access to your admin pages. Of course I understand if you don't want to give some stranger access to your admin pages, but it would be easier to locate the problem if I could look through the pages.