JBoss Tools 2.0.1 GA is shipped with RichFaces 3.1.4GA. The comboBox was first time introduced in 3.2.0GA. So, you have to upgrade RichFaces is you want to use it.
Hi Sergey. Thank you for your answer. I'm trying to find out how to manual install the 3.2.0GA with Eclipse. Do you know where I can find this??
Ask on the JBoss tools forum.