Hi all (again), I'm able to send a valarray with the XML archive but I have a problem with the Text archive. I displayed the received size in valarray.hpp. template void load( Archive & ar, STD::valarray<U> &t, const unsigned int file_version ) { collection_size_type count; ar >> BOOST_SERIALIZATION_NVP(count); cerr << "Received size : " << count << endl; t.resize(count); if (count) ar >> make_array(detail::get_data(t), t.size()); } I have a correct "512" with XML but I have "0" with Text. But the message received is like "0 1 0 0 512 2 2 2 2 2 ...". So it seems that the message is correctly sent. Is the valarray with text buggy or I missed something (I'm quite sure this is the second option). Regards, Thomas DAVID