Guys, I finally managed to save the slider settings - the reason why it was not saving is that my cfg files were marked as read only.
Now the reason they were marked read only is that if this option is left unmarked, Groovymame would delete my settings at the next startup. So my make-do solution for the time being was to delete a cfg file, set up a game all in one go (controls, sliders) then exit the game and put the file into read only before the next time I would launch that game to prevent the settings from getting deleted. I have a feelin its something to do with the read / wriote config options in mame.ini - any ideas?
MK and Smash TV are configured and now display and play fine. What I noticed is that for certain Capcom games (SF2, Ghouls and Ghosts etc) I have slight black borders to the left and right of the image and am unable to remedy this with the sliders. I am unable to stretch the image over the black bars with the sliders - rather the image goes 'under' these black bars. Would be greatful for any insight you may have into this/