Well this is certainly an interesting bug, as I've played this game for years on SNES9X without problems.
It's not the button itself, as I can use it (A) during combat and for dialogue just fine. It is only when I have the ring menu open does pressing the same A button cause the rom to restart.
I checked the button config to no avail, then reassigned all the buttons just in case; still nothing.
The only thing I can think of now is that there is some option within the preferences that is causing this conflict, and it only seems to have for Seiken 3.
Got any ideas, anyone?