[boost] [1.35] filesystem: missing #include <boost/filesystem/cerrno.hpp> ?

When building filesystem in a using an MSVC 9.0 IDE project I encounter compilation errors when compiling libs/filesystem/src/exception.cpp when it tries to: #include <boost/filesystem/cerrno.hpp> on line 19. The above header doesn't seem to be present in my unpacked 1.35.0 tar.gz. Am I missing something obvious here? Thanks, Mat