How to switch PAL PS3 to NTSC while in SD display mode?

[f1reball]

Hey guys, is there any way (CFW, tool etc.) to switch your PS3 from PAL to NTSC while in SD mode? Why I'm asking: I just bought Sonic's Ultimate Genesis Collection and some other retro gems via psn, now I noticed that they don't exactly look what I expect on a LCD. So, since I kept my old CRT I thought why not hook the PS3 to it via my old PS2 RGB cable. It worked out real fine but I noticed choppy playback of all the games in above mentioned collection. Then I looked in the display settings, ONLY PAL is available So of course I think that this has to be the problem, the 60hz NTSC games are forced into PAL..or isn't it? Anyway, because I can't change PAL to NTSC in the official FW, I wanted to ask if there's a CFW or homebrew tool which can do this?

[Pereb27]

Rebug can do this (Region Settings in menu 2), or you can manually edit xRegistry.sys file.

EDIT : Actually, not sure if you can do this, you said you bought them via PSN, so you're on 3.70 right? You'd have to be on 3.55 or lower to change region.