Amanda, I'm not sure if your problem is the same as mine, but it sounds like it. I 'cured' mine by finding two very thin washers and putting them round the shanks of the knobs that hold the connecting arm in place. Then put the arm *above* the washers when you connect it to the main carriage, and screw down the plastic knobs. This lifts the assembly just slightly off the needles, and they no longer catch. It doesn't seem to affect the knitting at all.
Inger
February 2010