Index: src/error_code.cpp
===================================================================
--- src/error_code.cpp	(revision 80450)
+++ src/error_code.cpp	(working copy)
@@ -22,9 +22,6 @@
 #include <cstdlib>
 #include <cassert>
 
-using namespace boost::system;
-using namespace boost::system::errc;
-
 #include <cstring> // for strerror/strerror_r
 
 # if defined( BOOST_WINDOWS_API )
@@ -36,12 +33,14 @@
 # endif
 
 //----------------------------------------------------------------------------//
+namespace boost
+{
+    namespace system
+    {
 
 namespace
 {
-#if defined(__PGI)
-  using boost::system::errc::invalid_argument;
-#endif
+    
   //  standard error categories  ---------------------------------------------//
 
   class generic_error_category : public error_category
@@ -70,6 +69,11 @@
 
   std::string generic_error_category::message( int ev ) const
   {
+    using namespace boost::system::errc;
+#if defined(__PGI)
+      using boost::system::errc::invalid_argument;
+#endif
+      
     static std::string unknown_err( "Unknown error" );
   // strerror_r is preferred because it is always thread safe,
   // however, we fallback to strerror in certain cases because:
@@ -133,7 +137,9 @@
         }
       }
       std::string msg;
+#   ifndef BOOST_NO_EXCEPTIONS
       try
+#   endif
       {
         msg = ( ( result == invalid_argument ) ? "Unknown error" : bp );
       }
@@ -161,6 +167,11 @@
 
   error_condition system_error_category::default_error_condition( int ev ) const
   {
+    using namespace boost::system::errc;
+#if defined(__PGI)
+      using boost::system::errc::invalid_argument;
+#endif
+
     switch ( ev )
     {
     case 0: return make_error_condition( success );
@@ -401,10 +412,6 @@
 
 } // unnamed namespace
 
-namespace boost
-{
-  namespace system
-  {
 
 # ifndef BOOST_SYSTEM_NO_DEPRECATED
     BOOST_SYSTEM_DECL error_code throws; // "throw on error" special error_code;