ProductPromo with Cart Sub-total condition

[cqnunez]

I would like to ask some help in implementing the ff promo.

Every $50 purchase entitles you to a free product (for ex. PRODUCT_B).

I have PRODUCT_A with a price of $51.

I have defined a promo with the ff promo condition:

Cart Sub-total >= 50

with the ff promo action:

Gift With Purchase quantity="1.0" productId="PRODUCT_B"

If I had sold 2 pieces of PRODUCT_A for a total of $102 and hadn't defined
any useLimit for the promo, I expected to have 4 items on my shopping
cart, 2 PRODUCT_A which were bought and 2 PRODUCT_B which were freebies.

When I had tried this scenario on the demo ofbiz site, more than 2
PRODUCT_B were added as free items.

If this really is the correct expected behavior, would someone help me
define a promotion that would only give 2 PRODUCT_B for the scenario
above.

Any advice would be most welcome.

Thanks.