(I tried to file a ticket, but got cookie trouble. Therefore I post here. Sorry for the inconvenience.) i) warnings (unused parameter) (These warnings are with gcc, 4.2.1) boost/serialization/shared_ptr.hpp:116: warning: unused parameter 'file_version' boost/archive/shared_ptr_helper.hpp:110: warning: unused parameter 't' /boost/archive/detail/iserializer.hpp:474: warning: unused parameter 'ar' (and 't', same line) I also get lots of boost::archive::detail::<unnamed>::init_guid<XXXX>::g' defined but not used where XXXX is some class name of mine ii) maybe a 'bug' (code does no longer compile) Code that used to compile with Boost 1.40 does no longer compile with the 1.41 beta: (I had no time to investigate yet; in case it is obvious for you once you see the code I have decided to include this point in this posting): boost/archive/shared_ptr_helper.hpp:114: error: cannot convert 'const boost::serialization::extended_type_info_typeid<MEPfad>' to 'const boost::serialization::extended_type_info*' in return (where MEPfad is a class of mine) Best regards Christoph