I noticed that if I have code that is really long, the page will try to render all of the code and thus make the docs side (on the left) really narrow. It's pretty hideous. It looks like docco keeps the left side fixed. As a result, code may walk off of the screen on the right, but I think that is a more appropriate thing to do in this case.
Haven't seen this one, do you have a repro case handy?
nm, seeing this in heroku/pulse
Here is an example (even though you've already seen it, others may have not): http://raynes.me/hfiles/narrow.html
Observe this vs this.