diff -u -r boost/numeric/interval/detail/msvc_rounding_control.hpp /cygdrive/c/Users/schulte/boost/numeric/interval/detail/msvc_rounding_control.hpp
--- boost/numeric/interval/detail/msvc_rounding_control.hpp	2010-11-10 16:52:44.696786200 +0100
+++ /cygdrive/c/Users/schulte/boost/numeric/interval/detail/msvc_rounding_control.hpp	2010-11-10 16:01:56.730082700 +0100
@@ -79,7 +79,11 @@
   static void get_rounding_mode(rounding_mode& mode)
   { mode = msvc2hard(_control87(0, 0)); }
   static void set_rounding_mode(const rounding_mode mode)
+#if defined(_M_X64) || defined(_M_IA64)
+  { _control87(hard2msvc(mode), _MCW_EM | _MCW_RC ); }
+#else
   { _control87(hard2msvc(mode), _MCW_EM | _MCW_RC | _MCW_PC | _MCW_IC); }
+#endif
   static double to_int(const double& x) { return rint(x); }
 };