i'm not an expert by any means but i have suffered through some rather "fruity" estery beers when the ferment temp was too high (i'm talking 72 not 78). I made a wheat that fermented at 70 and it gives a new meaning to the word "banana". When I brew with ANY yeast I am not familiar with, I read the mfr website for the proper ferment temp range and try to keep it on the cooler side.
Also ... did you use cascade hops for both beers at the end? although i like cascade, i find the "grapefruity" a little much sometimes and have stopped dry-hopping with it, or using it too late in the boil. I think it overpowers what else there is in the beer and since that "nose" is the first impression you get when you pop that top, thats going to cloud your overall impression of the beer.