On the dev guide is written I can ask here about it. Yesterday I've updated the license package to rev 2 and updated the methods (to match new ones) in my code.
The application is the same, the only difference is that the first apk is the one available for download on the Market, and the second apk hasn't been uploaded to the Market because of this problem (is it a problem??).
Note: if I install the second apk and make a License Test Response with "LICENSED" message it does verify the license.
My question is: if I upload the second apk on the market, would it work?
I will answer my question, for those who have the same problem. Just tried and: Yes, it DOES work.