How about just tightening the inner limit screw about a 1/4 to 1/2 turn? Just keep doing this until you either (a) stop dropping the chain or (b) can't hit the small ring anymore.

If the only way you can get to (a) is through (b), then look at the larger picture. Here it is: http://www.parktool.com/repair/readhowto.asp?id=75

You may have to (c) find a new mechanic or (d) become expert at performing your own front derailleur adjustments.