This is a very simple suggestion, but is it possible you just need to have the derailleur adjusted? Maybe one of the limiter screws isn't right?

I got my first road bike in the spring of this year -- Felt with Ultegra, 27spd with triple chain ring (love the bike more than I ever thought it would be possible to love a bike <<sigh>>>...). When I first started riding more I was dropping the chain when trying to shift into the granny gear nearly every steep hill -- and in VT, there are a lot of big hills. Now, dropping a chain going up a steep hill when you're still new at the whole clipless business... not too much fun. I was convinced for some reason that the problem was related to having a triple, and was actually giving thought to swapping out the whole drive train for a double/10spd cassette. Stupid me. Took the bike in for a tune up, mentioned the problem, and they totally fixed it by tweaking the derailleur adjustment. Haven't dropped the chain since.

Good luck!