Hi, thanks a lot for you help. Unfortunately, adding a virtual dummy function to the base class (the only one I can alter directly in the library) didn't resolve the problem. So I don't know (didn't check the beta) if 1.41 will resolve this issue. I tried to track it down deep into the heap allocation but I don't have any experience at all with meta-programming and the MPL and gave up in the end. I found a quick (and dirty) fix, though, that helps in my case. Therefor, I wrote a specialization of boost::archive::details::heap_allocator for the eigen::Matrix<> classes that uses code that was reserved for compiler that didn't support the has_new_operator feature (which is obviously the case). namespace boost { namespace archive { namespace detail { template<typename Scalar, int Rows, int Cols> struct heap_allocator<Eigen::Matrix<Scalar, Rows, Cols> > { typedef Eigen::Matrix<Scalar, Rows, Cols> T; static T * invoke() { return static_cast<T *> (operator new(sizeof (T))); } }; }; }; }; Best regards, Stefan