Terri, I doubt that this has anything to do with Rally School or Pirka Minoko, we have used those Stages many times in the Rally Club (with a variety of cars) without anyone experiencing that problem.
HOWEVER:
I think I have had the same issue a few times, when running off-line. Occasionally it dumps back to RSCenter during the countdown. When I repeat the same stage it works fine, and it has happened on various Stages randomly. Usually it happens when I hit the throttle just as the guy calls out the countdown.
Here is my (totally uneducated) theory.
It may have something to do with simultaneously loaded sound files?? It seems to me to happen if I cause the engine sound to start revving at the very same time the guy calls the countdown number. I wonder if the sounds try to load at the same moment and it causes a momentary conflict. Who knows, just my observation.
I have found that if I wait until the countdown has started and gently apply the throttle before he gets to "Go", I don't have the crash.
Go figure, maybe I'm way off here, but don't know what else to offer.
BTW, in your other post in the "The Lightweights" thread, you were worried about the Stages since Rick "Had the same problem". Rick's issue was different, the Sweet Lamb Stage wouldn't even load for him, which suggests a totally different problem which may be related to that Stage only for his installation. In your case the Stages have loaded fine.