I enabled multispark on an M box recently, and have noticed I will occasionally get intermittent short to ground DTC's on random coils.

Because these ignitions are so slow to charge, and the ignition window narrows with RPM, it's actually possible to request too many events per combustion cycle as RPM increases, and short to ground will be detected because the coil is charging when it shouldn't be.

I have yet to throw my scope on it to verify.