[Boost-users] Porting from boost_1_33 to boost_1_36 exception

I just port a project from boost_1_33 to boost_1_36 on fedora core 6. After the program run a few minutes, it crashed and got a message: terminate called after throwing an instance of 'boost::exception_detail::clone_implboost::system::system_error

' what(): Already open

I searched the message from boost docs and google but has nothing useful. What does thi message mean? How can i catch the exception? -- Best regards, PangYongQiang