Steps to repro (on JSF RI 1.2, MyFaces Tomahawk 1.1.5, GlassFish v2 b58):

JSP:

<h:form id="myForm">
<t:commandLink id="clInsert"/
action="#{myBean.insert}"
value="Insert This!"/>
</h:form>

Java:

public String insert() {
// Some EJB actions here, looks nice
return "list"; // A working navigation case
}

JSFUnit:

public void testInsert() {
JSFClientSession client = new JSFClientSession("/faces/Insert.jsp");
JSFServerSession server = new JSFServerSession(client);

// t:commandLink pressed by JSFUnit correctly, EJB call is done perfectly, stuff is in DB
this.client.clickCommandLink("clInsert");
server = new JSFServerSession(this.client);
// Throws:
// java.lang.NullPointerException at org.jboss.jsfunit.facade.JSFServerSession.getCurrentViewId(JSFServerSession.java:61)
assertEquals("/jsf/autorelationtype/New.jsp", server.getCurrentViewId());
}