So I start X with a terminal and then "groovymame64 -v -md 4 nbahangt &> file.log", right?
Yes, but I like to type it in this order:
groovymame romname -v -md 4 >romname.txt
I selected "pal" since my diplay is a pal tv (as posted before).
I should better regenerate the switchres.conf and xorg.conf?
Well, that's something...
Just edit mame.ini and change the monitor_specs0 value for this one:
monitor_specs0 15625-16200,49.50-65.00,2.000,4.700,8.000,0.064,0.160,1.056,0,0,288,448