Hello boosters I am trying to build boost 1.31.0 with STLport 5.0 RC1 using MSVC 6 SP5. I already spend quite a long time on a very mysterious issue with no result, I hope you will be able to help me. When I build the boost libraries I have the following error messages: vc-C++ bin\boost\libs\filesystem\build\libboost_filesystem.lib\msvc-stlport\debug\s tlport-iostream-on\exception.obj exception.cpp C:\PROGRA~1\MICROS~4\VC98\include\objidl.h(9909) : error C2668: 'memset' : ambiguous call to overloaded function C:\PROGRA~1\MICROS~4\VC98\include\objbase.h(443) : error C2668: 'memcmp' : ambiguous call to overloaded function C:\PROGRA~1\MICROS~4\VC98\include\objbase.h(467) : error C2668: 'memcmp' : ambiguous call to overloaded function "cl" /Zm800 -nologo -GX -c -D_STLP_DO_IMPORT_CSTD_FUNCTIONS=1 -D_STLP_DEBUG=1 -D _STLP_DEBUG_UNINITIALIZED=1 /Z7 / Od /Ob0 /GX /GR /MDd -I"bin\boost\libs\filesystem\build" -I"C:\Utils\boost_1_31_0" -I"C:\ Utils\STLport-5.0.0\stlport" -I"C:\Utils\boost_1_31_0" -I"C:\PROGRA~1\MICROS~4\VC98\include" -Fo"bin\b oost\libs\filesystem\build\libboost_filesyst em.lib\msvc-stlport\debug\stlport-iostream-on\exception.obj" -Tp"C:\Utils\b oost_1_31_0\libs\filesystem\build\../src/exc eption.cpp" This only happen during boost build process with STLport 5.0. When I use both boost and STLport 5.0 in a simple test that call memset there is no ambiguity. Is there any special treatment within boost code for memset and memcmp? I also notice, looking at the command line, that STLport include path is not first. Is there a special reason not to have it first? If I want to test how can I make it first? Bests