Not sure if this was already told to you in this thread but with duplex releases all you have to do is go into the usrdir of the game delete the eboot.bin file and rename the eboot.bin.orig to eboot.bin and you now have a clean eboot with no duplex loading screen. If the game is in ISO format you'll first have to extract the contents of the iso, and then rebuild it once the eboot has been changed.
Thanks, but I find out myself. The problem is that some of the downloaded games come only with the modded EBOOT.bin or the original EBOOT.bin for some reason makes the games unbootable or with other problems.