I've mentioned this before, but I think it needs to be redone again....
If you want to post, the easiest way to do it is to go into the topic of interest (Football, Off Topic, etc) and then push the button '+ New Topic'. This will automatically tag the new topic with the correct category and no issues of going to 'Uncategorized'.
The second way is to do it on the main page. This one is trickery. When you press the '+ New Topic', besides the information you want to post, you have to make sure that you give the correct category right next to where you insert the title of the topic. If you don't do it, or it defaults to 'Uncategorized', your post may end up in the wrong place and be killed about 60 minutes after the post.
Seems they could have done a better job with the second method.