I'm sorry that these 2 versions confuse some people, at the time I improved this module I contacted the author to know if we could put efforts together, I never had responses, that's why I begin on my own. And, to not confuse people, I renamed the module name (Improved discount coupon VS discount coupon), changed versions 1.5 (at this time the module was in 1.1 if I remember well) and posted in ubercart instead on drupal (in addition CVS account is annoying for me that don't understand CVS at all ^^).
I contacted the author when I finished this module, no reply, and I saw, later, that he did an 1.5 version completly different of mine...
ATM, the module fit my need and I worked on another projects. Now, my main project is to upgrade the shop I for which I developped this module for D6, so, maybe I will need to update this module for D6, don't know yet. But if I do it, I will take a completly other name to not confuse people.