There are at least four bands that go by the name of Upside Down:
1) Shortlived Mid-90s UK Boyband who found fame after winning a breakfast tv search, and had hits with songs such as the delightfully awful, "Change Your Mind";
2) Polish postpunk / melodic hardcore act, started in 1992 and still kicking.
3) Romanian New Wave/New Metal band: http://www.myspace.com/upsidedownband
4) 90's Death/Grind band from Czech Republic