JSF2 upgrade to existing project

Im tring to upgrade existing project JSF2.I faced so many problems with combination of SUN RI and myfaces so i eliminated all SUN RI's from classpath now combination of facelets and myfaces is giving problem. I wanted to know if we eliminate facelets and make use of just apache myfaces what should be the taglib namespace?? im getting this error

        27 Dec, 2010 7:08:28 PM org.apache.myfaces.view.facelets.FaceletViewHandler handleRenderException SEVERE: Er开发者_如何学Goror Rendering View[/login.xhtml] 

        java.lang.NullPointerException at org.apache.myfaces.view.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:57)
         at org.apache.myfaces.view.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:45) 
        at org.apache.myfaces.view.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:322) 
        at org.apache.myfaces.view.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:369) 
        at org.apache.myfaces.view.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:363) 
        at org.apache.myfaces.view.facelets.tag.UserTagHandler.apply(UserTagHandler.java:116) 

    at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:51) 
at org.apache.myfaces.view.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:57) at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:51)

Please help me if anyone worked on JSF2 upgrade..

I'm currently working on a JSF 2 / Facelets project using MyFaces 2.0.2. I have only the myfaces-impl and myfaces-api JARs plus some from Apache Commons in the classpath.

My Facelets namespace declaration is xmlns:ui="http://java.sun.com/jsf/facelets".