Play framework with Postgres. Error in column name

I am trying to create a simple application using play Framework 2.5 with postgresql. The idea is to save new entries in a table.

The database contains two tables. A journal is connected to a reference in a manyToOne relationship, so a reference must always have a journal. Both tables have more fields, but in summary they look like this:

CREATE TABLE reference (
reference_id integer NOT NULL,    
journal_id integer NOT NULL
title character varying(512));

CREATE TABLE journal (
journal_id integer NOT NULL,
journal_title character varying(128) NOT NULL);


ALTER TABLE ONLY reference ADD CONSTRAINT reference_journal_id_fkey FOREIGN KEY (journal_id)
REFERENCES journal(journal_id) ON UPDATE CASCADE ON DELETE RESTRICT DEFERRABLE INITIALLY DEFERRED;

I have mapped the tables to Play like this:

Reference.java

import com.avaje.ebean.Model;
import com.avaje.ebean.*;

@Entity
@Table(name="reference")
public class Reference extends Model{

    @Id
    public Long reference_id;

    @ManyToOne
    @Constraints.Required
    public Journal journal;

    @Constraints.Required
    public String title;

Journal.java

import com.avaje.ebean.Model;
import com.avaje.ebean.*;


@Entity
@Table(name="journal")
public class Journal extends Model {
    @Id
    public Long journal_id;
    public String journal_title;

    @OneToMany(mappedBy = "journal")
    public List<Reference> journal_references = new ArrayList<Reference>();

    public static Find<Long,Journal> find = new Find<Long,Journal>(){};

    public static Map<String,String> options() {
        LinkedHashMap<String,String> options = new LinkedHashMap<String,String>();
        for(Journal j: Journal.find.orderBy("journal_title").findList()) {
            options.put(j.journal_id.toString(), j.journal_title);
        }
        return options;
    }

plugins.sbt

addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.5.4")
addSbtPlugin("com.typesafe.sbt" % "sbt-play-enhancer" % "1.1.0")
addSbtPlugin("com.typesafe.sbt" % "sbt-play-ebean" % "3.0.1")

Build.sbt

lazy val root = (project in file(".")).enablePlugins(PlayJava)
lazy val myProject = (project in file(".")).enablePlugins(PlayJava, PlayEbean)
libraryDependencies ++= Seq(
  javaJdbc,
  cache,
  javaWs,
  "com.adrianhurt" %% "play-bootstrap" % "1.0-P25-B3",
  "org.hibernate" % "hibernate-entitymanager" % "4.3.8.Final"
)

libraryDependencies += "postgresql" %  "postgresql" % "9.1-901-1.jdbc4"

routesGenerator := InjectedRoutesGenerator
fork in run := true

The view is created correctly, it shows the proper fields and a select with the journal names from the Journal table.

create.scala.html

@b3.form(routes.Reference.save()) {

<fieldset>
    @b3.text(referenceForm("title"), '_label -> "Title", '_help -> "")

    @b3.select(
    journal_referenceForm("journal.journal_id"),
    options(Journal.options),
    '_label -> "Journal:",
    '_default -> "-- Choose a Journal --",
    '_showConstraints -> false,
    'multiple -> false ,
    '_help -> ""
    )

    @b3.free(){
    <input type="submit" value="Save the Reference" class="btn btn-primary"> or
    <a href="@routes.HomeController.index()" class="btn">Cancel</a>
    }
</fieldset>
}

When running the application I get the message "Database 'default' needs evolution! An SQL script will be run on your database -". The problem is that the field journal_id is renamed to journal_journal_id in the script.

Create table core.reference (
journal_reference_id          bigserial not null,
journal_journal_id            bigint,
title                         varchar(255)
constraint pk_journal_reference primary key (journal_reference_id));

And of course, when trying to save a new entry, I get the error that the field journal_journal_id doesn't exist in the table reference. I have checked the names in the database and the models and they are correct. I have also regenerated the script many times without success. I have no much experience with play so I have no idea what the source of the error could be.

Thanks in advance ! Any help is greatly appreciated.