How do I make the Usergroups work?

I've been fiddling around with the permissions, even in advanced mode. I check all of the boxes, and I save. Despite this, nothing happens. People are still unable to post in the sections of the forum that I have restricted, and the next time I look at the permissions for the group that I edited, they are all unchecked once again. I can't make moderators either. I've done this over and over. Even had a friend look at it for me, but we can't make it work. What's wrong?

mm..it's weired,,,,and your friend does he/she has the same board?!..an editboard?!