You can adjust the front derailleur, to change that. But it shouldn't be a problem except on the one or two extreme gears on the rear; given what you say, I infer (perhaps not correctly) that you are hitting on a lot more gears, or that it isn't centered.

Try adjusting the front derailleur so that it only hits when crossed to the one or two most extreme gears; that should help. Otherwise you might have to change your gearing (which is not hard).