I didnt understand your solution... You call on_thread_exit in the end of the threads that are created with boost::thread ? Even if there are, possibly, other(COM) threads running?

It has nothing to do with boost::thread. I call on_thread_exit on any threads that use boost::thread_specific_ptr. on_thread_exit can be called multiple times so this workaround works with boost::thread too. One thing important is you cannot use boost::thread_specific_ptr after the call. I would consider this as a hack not a solution. Sean