Product name issues

Hi everyone
i'm having some troubles with the playersetting in Unity 4 Pro.
Everytime i build my apk this comes out with the wrong Product name (the first i've used) and i can't change it anymore
i've tried to change it many times in the playersetting's ispector, but don't works..
there is a way to fix this drawback? maybe with another plugin or something..
the problem is that i can't install 2 or more builded apk on my device cause of this..
Thanks a lot