When sitting on the bike normally, the chain jumps off the smallest ring to the rear left (but by my right foot) and gets stuck against the frame. It looks like there isn't enough space and the LBS guy said the same thing, but it actually gets jammed against the frame and the smallest ring. The chain sought of forces its way into that spot which makes it difficult to get it out. It sounds like the high-limit screw adjustment might be the answer. Thanks again.