I searched the open issues for "sit" and for "sit + stand", and amazingly did not see anything about this bug. Many times (overall, I would say at least half the time) that I sit down, I stand up again immediately. I have had to do as many as 4 "sit-downs" in a row to overcome this !! This also happens on "/q"....I type it and maybe do a bio while logging off, only to come back and find my toon standing there.