I noticed a typo in the assignment operator for the cobject_id class in libs/serialization/src/basic_iarchive.cpp class cobject_id { public: cobject_id & operator=(const cobject_id & rhs){ bis_ptr = rhs.bis_ptr; bisp_ptr = rhs.bisp_ptr; file_version = rhs.file_version; tracking_level = rhs.tracking_level; ==> initialized = initialized; // [line 101] return *this; } ......... }; This could perhaps be part of the bug/problems Martin Ecker had(?). // Fredrik Blomqvist