You should really be using the generic downgrader, no?

http://downgrader.lan.st/GENERIC_DOWNGRADER_(2.71).rar

Install the app, download the 1.50 update EBOOT.PBP, rename it to UPDATE.PBP, and put it in the same directory as the main executable. (Not the folder with the % on the end).

Run from the Game menu via HEN.

__________________