there is a big problem to play avi and flv file in nokia 5800 xpress music . now it is very easy with JULY PLAYER 1.03. its very good player for nokia 5800 .it plays all file like mp4, 3gp, vob, avi, flv, wmv all types; This is a freeware trial version but u can bur or try to free key for july player 1.03 from its site www.julyplayer.com. this player is more good then smartmovie player. it has all features. and its very useful.