I have tryied the next thing:
I have uncompress the jar and I have copied the properties file to my i18n folder. I have configured my web.xml with the next sentences:
<context-param>
<param-name>jmesaMessagesLocation</param-name>
<param-value>
WEB-INF/i18n/jmesaResourceBundle
</param-value>
</context-param>
But the messages appear in spanish. Could it be a bug?
Thanks