@Horscht: I tested yesterday Free MCBoot 1.2c and had the same problems like you. I tried the build in HD-Loader and mine which works fine with my Memor32 and the Memento firmware. Both HD-Loader couldn't boot Gran Turismo 4 (and other games I tried) when I used the MC with Free MCBoot.
Today I made a new HD-Loader with the tools in this thread:
(I got a error message under Win XP, so I had to use this file instead: http://psx-scene.com/forums/attachme...7&d=1176226393).
Packed the file with the new Neural Pack and everything works fine now with the new HD-Loader and Free MCBoot. I can send you my "version" of HDL if you wish.
The language problem lies IMHO in the fact that HDL is a NTSC program and not PAL. Maybe there's no language-check inside of some games when it's started in NTSC mode (e.g. MotoGP4 starts from the original DVD in german and from HDD in english).