In VM 1.1.4, when using "List box" options for child products, the add to cart buttons are missing, whether you choose "One Add to Cart Button" or "Add to Cart Button for each Child" option. Furthermore, availability info is missing also. Everything is working perfectly if you use the dropdown list instead of the list box. Seems that in the latter case, the theme configuration settings are completely ignored. This is strange, i don't remember noting this in 1.1.4RC.
Noticed that this happens when there is no price for the parent product. If you select a price then the buttons show up, although this doesn't sound very convinient.
My parent products have pricing & I'm still not getting the Add to Cart to show up
I am also having this issue. Has it been resolved elsewhere?