Originally Posted by
operator
A properly setup front derailleur will not allow your chain to be thrown no matter how you shift. It's a derailleur adjustment problem.
I concur. If by now you don't trust your local shop to adjust your derailleurs properly, Shimano has step-by-step instructions on the web:
http://bike.shimano.com/publish/cont...tech_tips.html. Read "Front Derailleur Installation" and "Trim Function."