[Duplicate] Mixed Attributes ON - Quantity Discounts - not calculating correctly

ZC 138a
Fresh Install, Demo store
No addons
Totally uncustomized
Prob started right after install

1. Did fresh install of zc138a and enabled the demo store

2. Added an item called Widget 1:

Price: $100.00
Weight: 1 pound

3. Added Color Attribute from native selections: 9 colors, black default, no pricing features for attributes

4. Added 5 Quantity Discount boxes:

2:$90
4:$80
6:$70
8:$60
10:$50

5. Added "Widget 1" to shopping cart:

1 Black
2 Blue
4 Brown

6. With "Discount Qty Applies to Mixed Attributes" OFF, shopping cart shows:

1 Black - $100.00 ($100.00 each)
2 Blue - $180.00 ($90.00 each)
4 Brown - $320.00 ($80.00 each)

All above is correct

7. However, with "Discount Qty Applies to Mixed Attributes" ON, shopping cart shows:

1 Black - $70.00 ($70.00 each)
2 Blue - $160.00 ($80.00 each)
4 Brown - $$280.00 ($70.00 each)

See the "2 Blue - $160.00 ($80.00 each)" ?

Rather, that should be:

2 Blue - $140.00 ($70.00 each) with Discount Qty Applies to Mixed Attributes ON (if I understand things correctly)

Isn't this a duplicate of this other duplicate? http://www.zen-cart.com/forum/showthread.php?t=109077

Oh, geez, sorry.....