Hello I am testing boost 1.31.0 build under MSVC6 SP5 using STLport 5.0 RC1. In libs/filesystem/src/operations_posix_windows.cpp strcmp, remove and rename symbols are imported within std namespace before being defined (check comment next to the cstdio file inclusion). According the comments in boost/config/stdlib/stlport.hpp STLport do not grant all the necessary symbols within std. If there are others than the one fixed in this header don't hesitate to report on the STLport forum. Bests.