awo coupon pro payment method issue

hi,
i bought awo pro and now when i create a coupon with global discount and i put the price ( with 20%tax) included like on shop i add it into basket ...insert coupon name and go to confirm with 0,00 Euros to pay i get: select a payment method!!!

On awo coupon free that didnt happen

please help

joomla 1.5 and virtuemart 1.1.5

UPDATE.
on certain products i got this..i tried now with a different product and worked..is a problem with decimals or something?

try this:
https://awodev.com/forum/awocoupon/help-section/coupon-value-being-rounded#comment-345

thanks..fot the reply but i dont find the line on ps_coupon_process unders assets/virtuemart

sorry, I sent you the wrong link here is the right one:
https://awodev.com/forum/awocoupon/help-section/coupon-value-exceeds-total-order#comment-335

the should fix rounding errors when a coupon makes the order total 0.

i dont know why..i tried all fixes u suggested..but when i put a product old or not with 1.95 euros include tax and i put same on coupon i get select a peyment method on final confirm order with 0,00 on total

if you can send me a pm with ftp/admin access, I can take a look at it.