Hi, I'm trying to compile a code sample using boost signals on Windows using Visual Studio 2008, that works fine on Linux using gcc. My application crashes at the first time a signal's operator() method is called, and it seems that the issue is with some STL-related iterator magic. The application breaks in named_slot_map.hpp, in the call to boost::signals::detail::named_slot_map_iterator::init_next_group(), basically in operator== of class _Tree_nod, in file xtree - probably an MS STL implementation. basically it breaks here: #if _HAS_ITERATOR_DEBUGGING if (this->_Mycont == 0 || this->_Mycont != _Right._Mycont) { _DEBUG_ERROR("map/set iterators incompatible"); _SCL_SECURE_INVALID_ARGUMENT; } #else I tried to search on the issue, and found this thread: https://lists.secondlife.com/pipermail/sldev/2008-July/010867.html this even specifying _SECURE_SCL=0 doesn't help. I'm using boost 1.35.0, linking againts libboost_signals_vc90-mt-1_35. at the time of the call, actually there are no listeners bound to the signal. Is this an issue with boost::signals? or with MS VS? Akos