serious Virtuemart 2 error when using AwoCoupon Pro - when checkout is zero

I hav also posted this in the virtuemart forum today.

I am using AwoCoupon Pro to provide gift vouchers on a website.
It works great with VM2 2.0.14- the lastest version today.
However there is a major bug, which makes virtuemart completely unuseable.

Example
A customer has a gift voucher for the value of £50 and uses it to purchase goods with a smaller value, lets say £25.
When they have entered their coupon code, they will be left with no balance to pay (zero).
When virtuemart checkouts and sends the information to payment gateway it will always come back with an error as you cannot process a transaction for the amount of zero. (I am using sagepay, but you will get a similar error from paypal etc)
Surely I am not the only person who has this problem? I have been scouring forums for an answer, and so far I do not have one.

Can anyone help?

Thanks,

Tom.

Hi Tom,

No, you are not the only one with this problem. This is the best solution we came up with, using paypal as the payment method:
https://awodev.com/forum/awocoupon/help-section/error-coupon-equal-sales-price#comment-2981

Hi Seyi, thanks for the reply, I'd seen that thread before.
Is there a way/option to make the awocoupon code apply only to the products being bought, and not to include the shipping cost?
If this is possible, then at least the shipping fee would be passed through to the payment gateway?

Regards,
Tom.

Yes, if when creating your gift certificate template you select a specific asset. So if you want all your products to be discountable with a gift certificate then select all your categories or manufacturers, or vendors in the coupon. Shipping will be excluded.

Thanks, this looks like it may work for me, I will give it a try today.

Thank you,
Tom.