--- boost/boost/config/compiler/visualc.hpp	2012-03-28 15:57:17.000000000 -0400
+++ boost/boost/config/compiler/visualc.hpp	2012-05-15 16:29:46.000000000 -0400
@@ -219,6 +219,7 @@
 #  define BOOST_ABI_SUFFIX "boost/config/abi/msvc_suffix.hpp"
 #endif
 
+#ifndef BOOST_COMPILER
 // TODO:
 // these things are mostly bogus. 1200 means version 12.0 of the compiler. The 
 // artificial versions assigned to them only refer to the versions of some IDE
@@ -268,7 +269,8 @@
 #   endif
 # endif
 
-#define BOOST_COMPILER "Microsoft Visual C++ version " BOOST_STRINGIZE(BOOST_COMPILER_VERSION)
+# define BOOST_COMPILER "Microsoft Visual C++ version " BOOST_STRINGIZE(BOOST_COMPILER_VERSION)
+#endif // #ifndef BOOST_COMPILER
 
 //
 // versions check: