Last year I put a new chain on one of my bikes, and immediately could not pedal 20 feet w/o sucking the chain up into the FD on the middle ring. So I put the bike back on the rack and ordered a new middle ring.

It arrived, I installed it...then promptly found the small ring was doing exactly what you described. ARGH!!! So I had to order a new small ring.

Next time I'll test *all* the rings when such a problem surfaces, so I don't need to disassemble the crankset twice.