Ok thanks for the explanation. The weird thing is, this same rom file used to work fine a while back using LB. As far as I know, nothing else has changed but my version of LB. I'm using mame64 v.175 and the same mwalk.7z file as before. I just tried deleting the game from LB and reimporting, making sure to choose North America and it's still launching a distorted version of the ROM (sounds are strange and it's very slow and off-center). But when I go into mame64 directly without involving LB and choose the US version (or a few other versions), it loads up correctly. So confused