Hmmm... seems to work with the following settings. Can anybody confirm this?

<xa-datasource>
<jndi-name>infodeskDS</jndi-name>
<xa-datasource-property name="DatabaseName">localhost/3055:c:/database/infodesk.fdb</xa-datasource-property>
<xa-datasource-property name="Encoding">UTF-8</xa-datasource-property>
<xa-datasource-class>org.firebirdsql.pool.sun.AppServerXADataSource</xa-datasource-class>
<user-name>infodesk</user-name>
<password>infodesk</password>
<min-pool-size>5</min-pool-size>
<max-pool-size>20</max-pool-size>
<track-statements></track-statements>
<metadata>
<type-mapping>Firebird</type-mapping>
</metadata>
</xa-datasource>