When namespaces are used in a QtScript, there is need to prefix the functions with the namespace. E.g., XX::clsB getB() as it needs to match the type registered with qScriptRegisterMetaType().

The QMetaType typesystem is based on string matching, so even though the function is already defined within the XX namespace, Qt does not know that at runtime. Hence, the strings must match exactly.

Ideally namespaces in QtScript is document in a page like:
http://doc.trolltech.com/qt/qtscript.html