Hi Christian!

First of all thank's for your hint.

Finnaly I found the solution!!! :)

After debugging across the swing components I find out that is enough
if one of the component in the component hierarchy to not be visible
for not to show by the renderer.

By first shot I overwrited the java.awt.Component's isShowing() method
to always return true. This brought immediately the desired result.

Here is the JTextPane that will be shown by the cell renderers:

public class TestTextPane extends JTextPane {

    public void paint(Graphics g) {

        Container comp = getParent();

        while (comp != null) {
            comp.setVisible(true);
            comp = comp.getParent();
        }
        super.paint(g);
    }
}

Lalo