Hi, at the demo site, I see the wrong working Generic Child Variant plugin.
Let's see the page http://demo.virtuemart.net/ and let's try how the plugin working. Choose a product with additional fields such as "Dress Shirt with tie". Choose a variant in selector as sample "DS-Small (40,83 €)" and go back to "Choose a variant" in selector.
We'll see how in the browse view a loading productdetails template.
(http://s019.radikal.ru/i612/1610/cb/77726dd15be8t.jpg) (http://radikal.ru/big/ojxp50f7dblw9)
I posted few minutes ago a similar bug naming the one you talk about too:
https://forum.virtuemart.net/index.php?topic=135818.0
As far as I know they are aware of the bug and is fixed in the SVN for next version.
Regards
Thanks, it is fixed now: http://demo.virtuemart.net/product-variants