Index: src/os/win32/fosi.c
===================================================================
--- src/os/win32/fosi.c	(revision 30548)
+++ src/os/win32/fosi.c	(working copy)
@@ -45,8 +45,10 @@
     Sleep( s*1000 );
 }

+#if __GNUC__ != 4
 void usleep(long us){
     Sleep( us / 1000 );
 }
+#endif

 #endif
Index: src/os/win32/fosi.cpp
===================================================================
--- src/os/win32/fosi.cpp	(revision 30548)
+++ src/os/win32/fosi.cpp	(working copy)
@@ -52,9 +52,11 @@
	Sleep(s*1000);
 }

+#if __GNUC__ != 4
 void usleep(long us){
     Sleep( us / 1000 );
 }
+#endif

 #ifdef __cplusplus
 }
Index: src/os/win32/fosi.h
===================================================================
--- src/os/win32/fosi.h	(revision 30548)
+++ src/os/win32/fosi.h	(working copy)
@@ -33,10 +33,10 @@
 #endif

 #define _XOPEN_SOURCE 600   // use all Posix features.
+#include <windows.h>

 #ifdef _MSC_VER
 #include <cstdio>
-#include <windows.h>
 #include <cstdlib>
 #include <cerrno>
 #include <cstring>
@@ -66,7 +66,10 @@
 #endif

     RTT_API void sleep(long s);
+
+#if __GNUC__ != 4
     RTT_API void usleep(long us);
+#endif

     typedef long long NANO_TIME;
     typedef long long TICK_TIME;
@@ -91,7 +94,6 @@
 #define ORO_SCHED_RT    0 /** Linux FIFO scheduler */
 #define ORO_SCHED_OTHER 1 /** Linux normal scheduler */

-#ifdef _MSC_VER
     //conflicts with another struct under MSVC
     struct oro_timespec {
         long tv_sec;
@@ -99,9 +101,6 @@
     };

     typedef struct oro_timespec TIME_SPEC;
-#else // MINGW32
-    typedef struct timespec TIME_SPEC;
-#endif

	// high-resolution time to timespec
	// hrt is in ticks
Index: src/rtt-config.h.in
===================================================================
--- src/rtt-config.h.in	(revision 30548)
+++ src/rtt-config.h.in	(working copy)
@@ -57,8 +57,8 @@
 #  define RTT_HIDE   __attribute__((visibility("hidden")))
 # endif
 #else
-   // NOT GNU
-# if defined( __MINGW__ ) || defined( WIN32 )
+   // Win32 and NOT GNU
+# if defined( WIN32 ) && !defined ( __MINGW32__ )
 #  if defined(RTT_DLL_EXPORT)
 #   define RTT_API    __declspec(dllexport)
 #   define RTT_EXPORT __declspec(dllexport)