Quantity price breaks per product

[noperdienope]

Hey everybody,

 

Now, i used the QPBPP add-on, (Quantity price breaks per product), and i noticed it didn't work with groups, so i made it myself. I made invisble products, gave them the discount values, and made a group table, linking invisible products to a group name. And then all normal products were linked to retrieve the price from the invisible product. It all worked out great, but now im stuck with this:

Lets say, we have product A and B, and their both in the same group, from invisible product Z.

Now when i set the price break on 4, and i order 4 A products, it works. But what do i need to do to make it work when i buy 2 A's and 2 B's, it gets calculated as 4X the Z product?

thanks in advantage!