I've been playing with this during the weekend. And I think the answer is in the library.
There is a bunch of "wait" values I can pass to the library to slow the action down.
I think there are some instructions on how to use is library.....but since I'm not a paying member of that site.....I don<t have access to them. =(
What strikes me as odd about the way yours is executing the code, is that the delay is dynamically changed within the arduino ide to reflect the speed of the board so regardless of what board or what speed you are running, it should end up being the same in the real world....
Could be an error in the libs that was given. That's where I would look.