Yep, I agree with Sue, sounds like too much weight on the knitting is
causing the patterning needles to do a "tuck". Especially if the yarn's
under so much weight it breaks - that shouldn't be happening!

Personally I keep on going with the ribber comb and weights until they
hit the floor - after that, I tend to just use the small claw weights
at either edge of the knitting, or roll up the ribber comb as Sue
suggested. By then, the weight of the knitting itself is more than
sufficient to ensure correct knitting.

Let us know how you get on.

Jane

(Rugby, UK)