Y a peut-être un autre problème aussi avec JFreeChart et les frames...
Voir la FAQ de JFreeChart parlant du problème de projets fonctionnant correctement sous windaube, et ne marchant plus sous linux.
L'url de cette FAQ:
[ Lien ]
"10. My web application runs fine on my Windows development machine, but when I deploy it to the Unix/Linux production server, it doesn't work. What is the problem?
Most likely your server does not have X11 running. This is a Java (AWT/Java2D) issue, not something that is specific to JFreeChart. There is some more information at Sun's website:
http://java.sun.com/products/java-media/2D/forDevelopers/java2dfaq.html
In addition, the following thread in the JFreeChart forum contains some useful information:
http://www.jfree.org/phpBB2/viewtopic.php?t=1012"
Bonne journée.