coupons and incorrect tax calculations

[jdubs]

When I use a 10% off coupon I come up with tax that is 5-10 cents off what it should be.

I found the thread below, but the changes have not addressed my issue
http://www.zen-cart.com/forum/showth...626#post713626

I edited the ot_coupon

I have DISPLAY_PRICES_WITH_TAX = false

I remove the discount before tax and tax applies to shipping + subtotal

Does not occur when I don't use the coupon code
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Example with no coupon and proper tax

Sub-Total: $100.00

United Parcel Service (1 x 2.00lbs) (Ground): $11.98

Philadelphia,PA tax rate: $7.84

Total: $119.82
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Example with coupon

Sub-Total: $100.00

United Parcel Service (1 x 2.00lbs) (Ground): $11.98

Discount Coupon: Liberty : -$10.00

Philadelphia,PA tax rate(7%): $7.06 <- should be (101.98 *.07 = 7.14)

Total: $109.04
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Any thoughts on what could be going on here? I am using 1.3.8 and it says it is current

My site is store.libertymuseum.org and I want to take it live, but I need to sort out this small issue.

[jdubs]

Update

I replaced my /includes/modules/order_total/ot_coupon with

The ot_coupon hosted by paulm on this thread and the tax calculates correctly. I'm not saying it is a total fix, but it is working as of now.

http://www.zen-cart.com/forum/showth...t=54847&page=5
File Type: zip ot_coupon-pm1.zip (5.0 KB, 260 views)