Firebird and AutoIncrement

I’m trying to use Liquibase 2.0.4 with Firebird 2.5, but the following directives do not create a complete generator in firebird.

I’m, expecting Liquibase to create the proper trigger and generator for the correct management of the autoIncrement ID column, but Liquibase fails at it. 

From the documentation it seems that Liquibase can manage autoIncrement columns with Firebird: what is wrong with my picture?


       
           
               
                   
           
               
           
           
       

That looks right. Is it outputting the problem SQL and do you know what it should be?

Nathan