This is the level titled "riddle me this riddle me that" and has the caption "Why is 6 afraid of 7?". I know the answer to the joke, but I haven't been able to figure out the un/pw combo. I've also read the chat transcript in the source, the forum pages, and the other level 78 post here, but nothing is jumping out at me.
Does anyone have a hint to push me in the right direction? Any help would be appreciated!