On line 11 of richfaces/renderkit/html/scripts/tree.js.faces: "....while(node&&Element.isChildOf(node,this.element))...."
causes the following error:
"Microsoft JScript runtime error: Object doesn't support this property or method"
Again, this does not occur in IE7 if we user 3.1.2.SP1. Only in all subsequent releases of RichFaces.
Also, the problem does not occur in FireFox for any release of RichFaces.