Wrong Tax on Virtual Products with Coupon

Ok, so this whole tax and coupons thing has been driving me crazy. I've been trying to find out why a few of my products would still calculate tax even though the coupon covered the entire product amount.

My BIG find is that it has to do with listing the product as a "virtual product, no shipping address required" under the product settings. If you DO NOT mark it as virtual, then the coupon properly calculates and realizes that it no longer needs to charge tax. Below are some examples.

Virtual Product:

Subtotal: $10.00
Discount coupon: - $10.00
AZ TAX 8.05%: $0.81
Free Shipping: $0.00
Total: $0.81

It should not charge sales tax if the product discount covers the full amount.

Product is NOT marked Virtual:
Free Shipping option is chosen when the Shipping window comes up.

Subtotal: $10.00
Discount Coupon: - $10.00
Store Pickup (Walk-in): $0.00
Total: $0.00

This is the proper way for it to calculate, but you have to require a shipping method which I don't want to have to do.

Has anyone found this bug? All of my regular (non-virtual) products calculate everything correctly with a coupon. It's just these virtual products that are giving me a hassle.

Are your Virtual Products Downloads?

If so, please read through the FAQs on Downloads in this thread at the bottom:
https://www.zen-cart.com/tutorials/index.php?article=71

Yes, and I found out that a download only product will automatically get free shipping, which is one of the reasons that it mis-calculates the tax. If it skips over the shipping page then for some reason it still wants to calculate the tax based on the full amount even though the coupon covers the full subtotal amount.

If I choose to have it as a "Special, Product/Download Combo" then it does not skip over the shipping page, and it properly calculates the coupon and tax. The only problem that I see is if for some reason the purchaser doesn't realize that they should have chosen one of our free shipping options because it will automatically choose the lowest calculated shipping.

Does all of that make sense?

I'm guessing that it is missing some kind of code, when it skips over the shipping page. Any ideas?

Oh, and I switched them all to be Virtual Products: NO and Always Free Shipping: NO, but it still calculates the tax wrong.

Changing the Always Free Shipping to Combo forces the shipping page. I have Store Pickup $0.00 as an option. Choosing that and then continuing onto the payment page then shows the correct amount and applying a coupon works perfect as shown in my first post.

What are the settings in your coupon module?
Admin->Modules->Order Total->Discount Coupons

and the tax module:
Admin->Modules->Order Total->Tax

and your "Basis of Tax" settings in Admin->Configuration->My Store

• Basis of Product Tax
• Basis of Shipping Tax

Ok, here are the settings.

Discount Coupons:
Sort Order: 280
Include Shipping: false
Include Tax: false
Re-calculate Tax: Standard

Tax module:
Installed: true
Sort Order 300

I really think that it is something in the code for when it skips the shipping page.