I just upgraded to the current CVS from 1.1.6.GA to get s:selectItems working.
I had to switch form
FacesMessages.instance().add(String id, FacesMessage facesMessage)
FacesMessages.instance().addToControl(String id, FacesMessage facesMessage)
FacesMessages.instance().add(String messageTemplate, Object... params)
This is the main breaking API change in CVS. I hated having to do that, but it had to be done.