Broken build with qtnamespace configure option

Qt 4.6.0 doesn't build when configured with the -qtnamespace option.
I configured Qt with the following command :

./configure -qtnamespace MyNamespace

The configuration completes fine, but the "make" step fails with the following error :

g++ -c -include .pch/release-shared/QtGui -m64 -pipe -g -pthread -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -D_REENTRANT -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/directfb -I/usr/include/libpng12 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -O2 -fvisibility=hidden -fvisibility-inlines-hidden -Wall -W -D_REENTRANT -I/usr/include/freetype2 -fPIC -DQT_SHARED -DQT_EDITION=QT_EDITION_DESKTOP -DQT_BUILD_GUI_LIB -DQT_NO_USING_NAMESPACE -DQT_NO_CAST_TO_ASCII -DQT_ASCII_CAST_WARNINGS -DQT3_SUPPORT -DQT_MOC_COMPAT -DQT_HAVE_MMX -DQT_HAVE_3DNOW -DQT_HAVE_SSE -DQT_HAVE_MMXEXT -DQT_HAVE_SSE2 -DQT_NO_OPENTYPE -DQT_NO_STYLE_MAC -DQT_NO_STYLE_WINDOWSVISTA -DQT_NO_STYLE_WINDOWSXP -DQT_NO_STYLE_WINDOWSCE -DQT_NO_STYLE_WINDOWSMOBILE -DQT_NO_STYLE_S60 -DQ_INTERNAL_QAPP_SRC -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_NAMESPACE=MyNamespace -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -I../../mkspecs/linux-g++-64 -I. -I../../include/QtCore -I../../include -I../../include/QtGui -I.rcc/release-shared -I../3rdparty/xorg -I/usr/include/freetype2 -I../3rdparty/harfbuzz/src -Idialogs -I.moc/release-shared -I/usr/X11R6/include -I.uic/release-shared -o .obj/release-shared/qgtkstyle_p.o styles/qgtkstyle_p.cpp
styles/qgtkstyle_p.cpp:205: error: specialization of 'template<class T> struct MyNamespace::QMetaTypeId' in different namespace
../../include/QtCore/../../src/corelib/kernel/qmetatype.h:191: error: from definition of 'template<class T> struct MyNamespace::QMetaTypeId'
styles/qgtkstyle_p.cpp:205: error: definition of 'static int MyNamespace::QMetaTypeId<MyNamespace::QGtkStylePrivate*>::qt_metatype_id()' is not in namespace enclosing 'MyNamespace::QMetaTypeId<MyNamespace::QGtkStylePrivate*>'
make[1]: *** [.obj/release-shared/qgtkstyle_p.o] Error 1