PLEASE HELP - someone midified my XBOX 360 and i have a burning problem...

Hi all, thank you for looking at my posting,
I sent my xbox to this guy in order to flash it and he did, i came home and burned like 7 backups and 2 of them worked, as for the other five its sais wrong region.
the questions are, is it a burner problem? beacsue mine does not support the booktype or what ever it is ( i really dont know about this thing but i checked if mine support this and its not. i dont mind to buy a new one that will support it), or maybe its a general problem that even if the xbox 360 flashed not everything works., or maybe the flashing wasn't good ? even though the guy is a pro and he do it alot.

how will i know what is the problem?

i really dont know what to do.

Thank you very much for your time.