If you have look at my original code, it does use BOOST_SERIALIZATION_SPLIT_MEMBER() inside the class (sorry the code doesn't intend with tabs nicely). I also have tried including both... #include <boost/serialization/split_member.hpp> #include <boost/serialization/split_free.hpp> but neither work. I assume that the split free is obviously used by the list data type as it's not intrusive, and the member one is what I should include and have been including. I'll look running the tests later when I get round to figuring out how to run them etc. I'll need to RTFM first though. From the regression thingy, it said MSVC++7.1 worked OK though. I think this could be a little bug in the library (I won't speak too loudly here as I'm still a C++ beginner, and therefore there's a good chance I'm still doing something very dumb), maybe someone else could confirm they get the same problem as me when trying to serialize an class member varaible that is a list of objects using load / save methods that are class members under VS.NET 2003, like in my example.... anotherwords I have class A with separate load/save members, and then I have class B which has a member inside it that is of type std::list<A*>. Sorry in advance if I break the threaded reply structure on this list. I didn't have the list mail me replies. I'm new to all this mailing list stuff. Jason