Moc file fails to compile under MSVC2008 and Qt4.4 if "using namespace" directive is used

If the "using namespace" directive is used with Qt specific code as exemplified below, the application doesn’t compile with MSVS2008 on Windows.
This behavior is reproduced on Windows Vista.

#include <QtGui>

namespace A
{

class AA
{
};
};

namespace B
{
using namespace A;
class BB : public QObject

{ Q_OBJECT signals: /* if we make foo as simple member function in spite of signal it complies*/ void foo(AA *a); }

;
};

#include "main.moc"
using namespace B;
int main()
{

BB b;
return 0;
}

It compiles without error on Linux and MSVS2005.