I'm not sure, and have to admit not noticing this before, but I think that a non permanently banned member can still read the boards but not post, i would have to check it, but i'm sure it says so in the guidelines or somewhere similar.
here you are
13. Violations of these Rules
13.3 Any member subject to a suspension will be permitted to read the forums, but not post.
well that's the rules, it doesn't seem much of a punishment does it, like i said never really noticed anyone on a short term ban looking in so never gave it a thought, perhaps that rule needs reviewing, now is the time to speak up