Hi, I found an error in the boost::thread::condition documentation. The member-function template <typename L, typename Pr> bool timed_wait(L& lock, const xtime& xt, Pr pred) is documented like this template<typename ScopedLock, typename Pred> bool timed_wait(ScopedLock&, Pred); The "const xtime&" parameter is discard. Regards David Callu