hmm...i doubt if the creatine/gatorade mixture caused that....
basically, if you get any type of creatine that is already mixed w/carbs and flavor-i.e. Phosphagen, Cell Tech, whatever it is essentially the same as mixing it w/gatorade.
I save myself the money and buy gatorade powder, and mix it with plain creatine. The carbs are supposed to enhance the creatine absorption in the muscles, and you should be taking carbs immediatley post workout anyway, so it makes a good postworkout combo.