One of my favourite games of all time Super Mario Bros 3 has seen a new rom hack recently and heres the fixed version of that hack, heres more details:

Super Mario Bros. 3: The Forgotten Worlds is now 100% tested and fixed. As a bonus, a poster has been attached, where you can read the fully worked out and improved plot.
As for those, who has downloaded and played this game, once again, sorry for having 4 worlds in the game. The SMB2J clone hack patch allowed only 4 worlds regularly and the idea/plan was 4 worlds originally, too.

download etc here --> http://www.romhacking.net/forum/index.php?topic=24534