optimine-1.4_01_inio.zip is not an official OptiMine version. Someone named Inio got tired of waiting for OptiMine to be updated to 1.4_01 so they did it themselves. http://web.archive.org/web/20110429020200/http://www.minecraftforum.net:80/viewtopic.php?f=1032&t=132717&start=1410#p3684727