The game has the latest English patch so no need to patch it again
https://rapidshare.com/files/2304242549/Monster_Hunter_Portable_3rd__JPN_.part1.rar
https://rapidshare.com/files/1467588554/Monster_Hunter_Portable_3rd__JPN_.part2.rar
https://rapidshare.com/files/3301498718/5.50_Prometheus.zip