[fixed 1.3.9a] Group Discount and Discount Coupon Tax Calculation Issue

[bobtabin]

Fresh Install fo Zen Cart 1.3.8a

I have a major tax calculation issue when using either a Discount Coupon or Group Discount (not together). This is what occurs:

Sub-Total: $69.00
Standard Shipping (Standard Shipping): $7.15
Group Discount: -$34.50
Florida State Sales Tax - 6.00%: $2.29
Total: $43.94

As you can see the total does not calculate correctly. 69.00+7.15-34.50 (50%)= 41.65 * 1.06 (tax) = 44.15 (6% tax on $41.65 should be 2.49, not 2.29).

What's going on? Here are my settings and more comments below. This occurs with both modules. How do I fix this?

Group Discount

This module is installed
true

Sort Order
290
Include Shipping
false

Include Tax
false

Re-calculate Tax
Standard

Tax Class
--none--

I have tried both None and Standard for Re-calculating Tax.

Some how the discount is being applied to the shipping to.

I am trying to only allow the 50% off on the Sub-Total and NOT the Shipping. I though my options were correct, but the group discount is being applied to the shipping. With this scenario, the tax calculates correctly. How to I only allow a 50% discount on the Sub-Total and NOT the Shippig too, as per my settings reflect? This is a bug.?