Hmm, this is a really strange situation. The reason I say that is because clearly your school took their discipline very seriously. Too seriously, if you ask me but that's neither here nor there.
From an ethics standpoint, yes, you should mention it. Especially if your transcript includes a grade that ties to your disciplinary record (which is, again, a little ridiculous).
BUT - honestly, it won't really matter at all. You stayed out too late one night and, in return, the university threw the book at you. With force, it seems. I don't think there is an adcom out there that is going to look at that seriously. Mostly because it's silly.
That question is really there to determine if you were ever caught cheating or suspended for another significant issue. If you didn't have a grade tied to this infraction, I would advise you to not include it. What Housing chooses to do to you isn't generally tied to your Academic record nor does it have anything to do with its integrity. However, because it dropped your grade to a B+ you should mention it.
Bhavik