Hi. I've been looking for an answer to this question for a while now, suspecting that since the last update I did to my machine caused the described behaviour (flash videos not storing themselves on /tmp.
Anyway, I found a thread here that stated the same question (http://ubuntuforums.org/showthread.php?p=9860374) and WTF, some admin copy/pastes some youtube's rules and closes the thread, not answering the question whatsoever. What's up with that?
So here I am, asking the same question, since it wasn't answered at all.
Thanks for your time.