SwingX and NetBeans 6.9.1 GUI designer (JXCollapsiblePane/JXTaskPane)

I am new in SwingX and I have trouble using JXCollapsiblePane and JXTaskPane using Pallete manager of Netbeans 6.9.1 Specifically:

For JXTaskPane:

1. I drag a JXTaskPaneContainer from pallete manager in a JForm
2. I drag a JXTaskPane from pallete manager into JXTaskPaneContainer
   3.I try to add a jpanel or a jbutton in the JXTaskPane but I get the message "Cannot enclose components in a non-empty container"
   If I add the components programmatically (as in example code I found i don't get an error and seems to work)

For JXCollapsiblePane:

1. I drag a JXCollapsiblePane from pallete manager in a JForm
2. I try to add a jpanel or a jbutton in the JXCollapsiblePane but I get the message "Cannot enclose components in a non-empty container"
   If I add the components programmatically (as in example code I found i don't get an error and seems to work)

Can someone please explain what am I doing wrong?Is it not possible to do this using the Netbeans pallete designer? I want to design my form visually. Is it possible for the components I am trying to use?

Thank you.

Solved it. The swingx-beaninfo.jar was missing from my project