Thanks again Marco for your answer. I have tried it as you told me, but I still haven't good results. I am using the version 1.4b4 of Jetspeed, Could it be this the problem? It's possible that Jetspeed could have a bug with wml portlets? (Problems aside from previously commented about Xreg archive and control tag).
If somebody has a wml portlet that works fine, please sends it to me to verify if I'm doing something wrong. Thanks to all for your collaboration. Jes�s
