Finaly i find the white screen bug.
I was useing VRAM_BANK_B for the lower screen but it seems that every card other than scsd don't like it. Now i use VRAM_BANK_C and all go the right way.
As soon as a i can i'll upload alla my ds program to my site.
ps:my site link is donotjava.altervista.org now it's a big set of university code,note and other thing, but for the 27 feb it will be a ds repository

see you soon!