Mark, encoding is there . "encoding=ISO8859_1" .
I had to use it when tried the first time jaybird 3 .

I have :
1. On Data Sources view, a data connection .
2. On Properties of project in Hibernate Settings as Default Hibernate Console configuration the one on 1.
3. On Properties of Project also, but on JPA I used con Connection "None".
For some reason when selecting the data connection here, the project "looses" META-INF/persistence.xml and project does not build.
 

In persistence.xml, i have :
    <persistence-unit name="myPU">
        <properties>
                <!-- DataSource & Connection info. -->
        <property name="javax.persistence.jdbc.driver" value="org.firebirdsql.jdbc.FBDriver"/>
        <property name="javax.persistence.jdbc.url" value="jdbc:firebirdsql://server:3050///path/to/data/mydbi.fdb"/>
        <property name="javax.persistence.jdbc.user" value="USER"/>
        <property name="javax.persistence.jdbc.password" value="mypasswd"/>
       
        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size" value ="1"/>
        <property name="hibernate.dialect" value="org.hibernate.dialect.FirebirdDialect"/>
        <property name="hibernate.connection.encoding" value="ISO8859_1"/>

        <property name="show_sql" value="true"/>
        <property name="format_sql" value="true"/>
        <property name="hbm2ddl.auto" value="validate"/>
       
        </properties>
    </persistence-unit>

I'll try to get eclipse error log .

Pablo