You might consider asking over at:
on the message boards.
Something to note... is that xbox style mini analog sticks are very poor when it comes to control. A flight stick
will yield better results, because you have better
physical leverage. (and many times, better positional
Your controller may have some sort of sensitivity
settings that you have to adjust in windows. Or at very
least, calibrate it in windows. (is the driver even loaded
for the pad?) It could also be acting as a digital
joypad (need to press a button to switch modes), or
it could be acting out as "Mouse mode". Again, modes
needing proper setting in the custom software, or the
correct button pressed.
Finally, for the sake of argument, certain analog games
used gearing in the controls. This would give them
superior accuracy, as it would turn the pot (sensor)
further distance. Depending on the type of pot used, and
if there is or is not gearing... (and even, in the case
of Sinistar, you do not have a specialized rubber-x
center spring...) you may have trouble playing certain
There are ways to interface real arcade controls to mame
in many cases. However, on some games, like 720, mame
does not allow a person to use a real controller at all,
as the driver is hacked up, with no compromises available
for those people who actually appreciate that/those games.
Anyways, best of luck.