Yep, breeding doesn't always make a mare calmer. Think diet and training would play a more important role. Hey, thanks for the tip on the mare magic. I see that Smartpac carries it in addition to moody mare supplements.
I too, have a mare that is a handful that I intend to breed, but not for purposes for calming her down. I think it's best to get her under control with diet and training before I attempt breeding. Ya know, double the trouble. Yikes, that wouldn't be good.