Hi folks,
Had one of the above quality sets in where disc chewing was the complaint. Was doubtful so inserted my fave Rutles disc and found it became neatly grooved along the outer part.
Due to the fact that few cable ties are used, the laser ribbon had become corrugated by all the other cables in the vicinity and rubbed on the disc.
Rutles disc saved by rubbing with 'Brasso' - as I initially didn't believe it I shoved in my 'North by North-West' - and am still rubbing.
It's all fun - Chris.