On the API key page ( http://osu.ppy.sh/p/api ) if you type enter on any part of the page, the osu! website believes that you want to reset your API key. This also happens for instance, if I'm typing in a username in the search on the top and then press enter in order to go to that user's profile. This has made me swear my ass of twice, because I had to go and search for all the places in which I've typed my API key in, replace it with the new one, and after I've finished doing that I have to cross my fingers because there might be some application I didn't remember of which inevitably broke.