I don't wish to interfere but the way this thread is going this could last for weeks. I assume we're talking about the Socata TB20GT Trinidad posted here.
http://www.simviation.com/fs2002props31.htm Bill Leaming, the creator, is an experienced FS developer & I would expect the flight dynamics to be as realistic as he can make them. The TB20 has a standard Lycoming piston engine. If anything the prop torque would make the aircraft swing to the left like the other default aircraft, not the right.
The problem could be with your joystick calibration. If you have Auto-rudder enabled I assume it doesn't have a separate rudder control. (If it has one you should disable Auto-rudder.) The swing could also be caused by a crosswind. This should affect all aircraft, not just the Socata. Without trying it myself I can't really figure out why this would happen.
I don't know if there is another version of this aircraft but I haven't looked. Hope this is some help.