Both the premium and the pro I play on location hit the ramp. Are there switches under the playfield that tells the game what position the cannon is in? Optos would be my guess. Similar to the bell.
Can you hit the right ramp with the cannon if you try? Can you hit the lower left A standup/drop target? Those are the most outside shots you should be able to make. I'm guessing both of you will answer yes and no to those questions, although not necessarily in that order. It sounds like one of you are slightly too far clockwise and the other is slightly counterclockwise to where you should be.