Problem with Zillion 2; The Triformation on Master System

[dcultrapro]

Hey guys, so I tried playing this again last night and for some strange reason whenever I seem to finish a stage in part 2 it seems to just revert to the title screen, has anyone heard of this? its not like a crash during the game, it should progress but simply returns to the menu. has anyone heard of demo version cartridges maybe? I mean mine doesn't say DEMO or anything so I have no idea. I'll upload a vid later on of my playthrough and you'll see what I mean

thanks

[zapiy]

How strange. Not something I have heard about before. Anything on the net about it?