DRAGoN.X wether you can play NTSC/PAL without problems is more due to the bios used, dashboard settings, msdash settings and a few more factors.
I can only play PAL games because my TV can't handle NTSC so I can never preorder games from the U.S or similar, too bad I spent money on a few games before noticing my TV couldn't handle it.
Perhaps your TV can handle both PAL and NTSC and your dashboard sets your xbox region to be PAL or NTSC depending on each game. It is likely to be that way and you can be happy...
For sharkfin it is not a BIOS problem that is for sure, the EvoX M8 bios is fine and has always been. It is the most supported and currently the best 1.6 bios out there. There is on the other hand a 1.6 version of the X2 5035 bios too but that one is not as stable as the EvoX IMO. I can play GTA: SA fine with my EvoX M8Plus bios on my DuoX2. It also works on my other xbox that has X2 4981 on an Aladdin Advance 32.... So not a bios problem that is for sure.
I still think it is a region problem. He must have gotten a copy from the wrong region for some strange reason.
@Sharkfin, is the game working as it should when you play from the disc?