Ok I see, sorry should have checked thread before.
What is required for a reproduction method?
I have reproduced it several times. But I have used the same tape every time I reproduced it. Not sure if that matters.
Ii seems to work ok as long as the tape is played backwards slowly (0 to -0,3V, when it reach -0,5V it happens if I remember correctly.) But perhaps it also has to do with distance between the cuepoints?