I bought a 20 secondhand ,working ok ,changed line and thread stripped.Got a new one from Daiwa (about £15),went again without warning a year later,got onto Daiwa to order another one and they said they have a two year warranty on parts so gave me another one.
As far as I know this was only a problem on the early models,on the later ones the collar on the back of the star has a groove machined into it.Have had no more probs with other Saltists I have.