This is definitely depends on your TV! List what it is and your HAS settings and plug in method to the OSSC.Raiden 1, 2 and DX share the weird sync (Think it was around 56Hz)
I love my HAS by the way!
Did bring me back to arcade gaming without all the cabinet troubles.
Now i can focus on PCB troubles ^__^
The easiest answer is going to be buy the OSSC Pro when it comes out, I think it wills love a million problems with weird sync and bootleg PCBs as well as being able to rotate games like Raiden to play on a horizontal LCD!
Another series you may have problems with in the future is Midway PCBs like Mortal Kombat, they also have a weird sync.