I don't snap that often, but I have a friend on there that has disappeared from my "sent snap" history. It's been about 2 months maybe and we've only sent a few snaps ever on there, but I have users that are on there from like 6-8 months ago and still show up in my history.
However, he still shows up when I click +chat, on my friends list, I can still see his score..
did he delete me? I can't think of a reason why I would be deleted so just curious, I find it weird that he is gone from my history but still show up everywhere else.