Why visible child product in front end?

[kontrasztplusz]

Hi,
I  worked a practicing webshop (Joomla 2.5.7). I use VM 2.0.6 and I updated VM 2.0.12. I used parent-child products. All front-end product views were good. The parent product is visible and the child product is invisible.
Today I deleted ,,old" Joomla and I installed a final Joomla (2.5.7) and VM (2.0.12b). I recreated parent-child products. Now all child products are visible, too in the front-end, but it's wrong.

What did I make worse? How can I set the child products can be invisible ?

Thank you.

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