Using the latest portable_binary_archive from the vault with boost 1.34.1 on Mac XCode 3 I'm getting a linker duplicate symbol error: ld: duplicate symbol boost::archive::basic_binary_oarchive<portable_binary_oarchive> ::save_override(boost::archive::class_id_optional_type const&, int) in .../Persistence.build/Debug/CxxTest.build/Objects-normal/ppc/AAA.o and .../Persistence.build/Debug/CxxTest.build/Objects-normal/ppc/BBB.o Any help in resolving this issue would be appreciated. This succesfully compiles/links and runs when built on MSVC 8. Thanks, Jeff