When you hear hoofbeats, think horses, not zebras
Found the problem with it,I tried every possible thing on Earth with it and finally the simplest solution pops up: it seems that the protection jump at $f03c0 a.k.a. the palette ram sub-routine is called with the wrong vector.Differences between this call and all the others is that the D2 register is not equal to zero but is equal to 0x0b00000.My 0,50 € guess is that the programmers added this extra “feature” to protect the most interesting thing of this game. 😛
Now I need to check the other two girls and if there’s consistency I have to add this to the sub-routine…