It's something that it very hard to find once some of your RichFaces pages are suddenly acting very weird, like sortable columns only sorting once and then ignoring all other requests. It turns out that the following configuration changes the way events and life cycle are handled, breaking AJAX.

<context-param> 

<param-name>facelets.BUILD_BEFORE_RESTORE</param-name> 

<param-value>true</param-value> 

</context-param>  

To spare you days of debugging through RichFaces component code and JavaScript, please heed this advice very well! ;)