[Boost-users] Project link error with Wave on OSX

I've just updated a project that was working under XCode 4 with boost 1.48 to XCode 5 and boost 1.55 (installed with MacPorts). Now I have a link error with Wave which wasn't the case before. This somehow baffles me as I thought everything was template based. I am also linking with libboost-wave.mt.a but that doesn't solve the problem. The linker errors are, among 6 others: Undefined symbols for architecture x86_64: "boost::wave::cpplexer::new_lexer_gen<__gnu_cxx::__normal_iterator, boost::wave::util::file_position, char*> > >, boost::wave::cpplexer::lex_token, char*> > > >

::new_lexer(__gnu_cxx::__normal_iterator const&, __gnu_cxx::__normal_iterator const&, boost::wave::util::file_position, char*> > > const&, boost::wave::language_support)", referenced from:

I've tried forcing std::string as the BOOST_WAVE_STRINGTYPE, but that just changes the signatures of the undefined symbols. I fail to see what has changed and I am completely stuck. I would have understood if I had a compiler error but this is a link error. Is this something to do with the standard C++ library? For my project, C++ dialect is C++98 and the standard library is libstdc++. Thanks in advance, Olivier