multiple conditions act weird

I tried creating a discount that applies only within a specific quantity of product. If someone buys 20 to 50 Kittens, they should get a discount.

Created two conditions on the discount.
First is >= 20 Kittens.
Second is <= 50 Kittens.
They are both in the same group.

In my tests, the discount gets applied starting at 20 Kittens.
25 Kittens also gets the discount.
26 Kittens does not get the discount.

If I change the second condition to 60 Kittens, I am able to add 30 Kittens to my cart and get the discount. But if I have 31 Kittens in my cart, I do not get the discount.

I've enabled the main Discounts module, and the Product discount module. "Discounts on individual products"
I'm using the uc_discounts module from 2008-Nov-20.