Avast does not detect Hoaxes - this term is used for the messages about non-existing viruses which spread among the users.
The situation with Jokes is a little bit different: sometimes it is very difficult to distinguish between say Trojan Horse and the Joke - it all depends on the current situation and on the sense of humor of the victim. If something says that it starts to format your hard disk and you immediately switch off your computer and loose your hard work, it is not so funny. Also - meny test beds of "AV Testers" contain a lot of so called Joke programs among other crap.
To make the story short - avast! detects several programs as [Joke] - mainly old ones. If the user does not agree with our detection, he might to exclude such program from the tests...
Pavel
