Hi, I tracked down a crash to a call to boost::lexical_cast (Boost 1.46.1( when using the Intel 12.0 compiler for Windows (embedded into MSVC8) if optimizations are enabled. I would have expected the mini-program below to work smoothly, but instead the second catch-handler is entered (unknown exception). The offending compiler option is /O; in all cases except of /Od [all optimizations disabled] the exception is raised. May I strongly suppose this is either a boost or an Intel compiler issue, or did I misunderstand something ? Below are full command-line compiler options and teh program. Thanks and best, Thomas command line options: /c /O2 /Og /Qipo /I "C:\Libraries\Boost\boost_1_46_1" /D "WIN32" /D "NDEBUG" /D "_CONSOLE" /D "_UNICODE" /D "UNICODE" /EHsc /MD /GS- /fp:strict /Za /Fo"ReleaseFinal/" /W3 /nologo /Wp64 /Zi /Qfp-speculation:strict /Quse-intel-optimized-headers /Qintel-extensions- mini-program: #include <iostream> #include <ostream> #include <string> #include "boost/lexical_cast.hpp" int main() { try { std::string X = boost::lexical_cast<std::string>(2 - 1); std::cout << X << std::endl; } catch (boost::bad_lexical_cast const &) { std::cout << "boost::lexical_cast exception occurred."; } catch (...) { std::cout << "An unknown exception occurred."; } }