Just got back from the shop. Everything is perfect now; the mechanic shifted the chainrings a couple of millimeters inboard by moving some spacers that were between the pedal and the BB. I took it for a short ride and the shifts in front are right where they should be.

The move to smaller chainrings makes the bike much more comfortable. Riding on the flats with the big ring up front now puts me in cog 5 or 6 instead of 3 (counting from biggest to smallest), plus I have a couple of handy extra low gears.