java.util.MissingResourceException: Can't find bundle for base name

Hi, I´m developping a swing application, and I want to internationalize it.

I have 3 resource files : languageText, languageText_es_ES, languageText_en_US.

My app crashes on the sentence
        java.util.ResourceBundle.getBundle("languageText",mLocale);
but only crashes when the application is compress in a jar file.

The structure of jar file are a package named  circOffline, with a main class named offline.
The resource files are in the same directory than jar file.

I have a windows folder called TEST.
The content of TEST are : the jar file; the 3 resource files; and a bat file to launch the application who contains "javaw -jar offline" (offline is the name of the jar).

I always obtain the error : java.util.MissingResourceException: Can't find bundle for base name languageText, locale es_ES.

However, if I uncompress the jar file and execute javaw circOffline.offline, all run fine.

The classpath of the machine, points to TEST folder.

Some idea ??