Ripping Questions

[Carpaccio]

Hey you lot, It's me again. I've been trying to rip the old way from Battletoads for Arcade via MAME. There's a problem though. An extremely annoying graphics problem. It prevents me from getting accurate sprites. The problem is, that when I take a screenshot from it, be it print screen or internally, there is a really obnoxious 'stretch' effect on the sprites. Now it's not very noticeable, but what it does is it 'splits' and 'doubles' pixels on the sprites. If one were to look at one of the toads in the shot, they will notice that the pixels are, for the most part, either stretched or flattened. My question is what settings must I have for accurate screenshot-based sprite ripping in MAME?

And yes, I'm well aware of the tile viewer built into certain MAME versions...however I have thus far been unable to find a version in which it actually works properly.