Apparently it was a problem with my database… I had to remove and re create it.
Is it normal than while connecting as admin if I go back to the last page with the arrow of internet explorer sometimes I go back to guest page? Is it also a bug of Alfresco when sometimes I connect to alfresco and have nul pointer exception and while retrying to connect that works fine?
I also get into troubles while importing my class sub-class of NewUserWizard. It seems that it is not possible anymore to do super.init() in my sub-class. Did I forget to add something somewhere? It was working fine with version 1.1.