You may need to copy the DragonRace as a nonflying variant:
DragonRace > NonflyingDragonRace (Turn "Flies" off in the copy)
and make your dragon of the NonFlyingDragonRace.
EDIT: I tried doing this yesterday. Been working on this for a long time. When I copied the dragon race, the copy race had no body for some reason. All the stats copied properly, but whenever I set my Dragon's race to the new race, it simply disappeared.
Anyway, to RandomNOOB, it appears the even wasn't working properly. I changed the event to OnInit instead of Onload, and it worked like a charm.