I am using VC++6 SP5, STLPort 4.5.3, boost 1.30.0. I am tring to use boost::filesystem::fstream objects in conjuction with boost::filesystem::path objects. When I create an ifstream object, the compiler gives the following message: error C2504: 'basic_ifstream<char,class _STL::char_traits<char> >' : base class undefined. Above error takes me to ln 47 in fstream.hpp. Similar problem with ofstream. Any suggestions? Thanks, Aaron Laws