There is another warning, this time from a compiler based on EDG 245 (Tru64 cxx): cxx: Warning: /net/taipan/scratch1/rwgk/auto_build/sources/boost/boost/exception/enable_current_exception.hpp, line 57: #768-D exception specification for implicitly declared virtual function "boost::exception_detail::clone_impl<T>::~clone_impl" is incompatible with that of overridden function "boost::exception_detail::cloning_base::~cloning_base" clone_impl: --------^ Just a throw() missing somewhere? Ralf