Product review (1 stars): it works as good as new now
After replacing two of these, I discovered why mine was breaking.  Bear with me, it works as good as new now.  The opposite end of the screw is held in it's plastic bearing by a plastic nut held in place only by friction (like a nyloc nut).  If, as the screw turns, the friction stops holding, then the auger screws through the nut changing the horizontal alignment.  Then the end of the screw now protrudes from the nut and rubs tightly against the outside of the bucket housing, and at the other end the cup is now not seated in its circular housing (part of the bucket) but has backed out so it easily gets kicked out of the housing by ice cubes.  Incredibly dumb design.  I took the whole thing apart and drilled a pin hole through the nylon lock nut/bearing nut and through the aluminum rod that goes through it.  I pinned it with a small nail so now when the nut is at the correct position to align the entire assembly, the nut cannot rotate and "screw" everything up.  Now the auger doesn't rub on the outside end and on the other end the cup is perfectly seated.  Works perfectly and is not going to get dislodged by ice or gradually drift out of alignment.  A tiny drill and a small nail.  Good luck.  A whole new mechanism with the same friction lock nut is going to eventually slip the same way.