diff -r 93b982ccede2 -r 5daf16870df6 src/multimedia/audio/qaudiooutput_win32_p.h
--- a/src/multimedia/audio/qaudiooutput_win32_p.h	Mon Jun 21 22:38:13 2010 +0100
+++ b/src/multimedia/audio/qaudiooutput_win32_p.h	Thu Jul 22 16:41:55 2010 +0100
@@ -61,6 +61,7 @@
 #include <QtCore/qstring.h>
 #include <QtCore/qstringlist.h>
 #include <QtCore/qdatetime.h>
+#include <QtCore/qmutex.h>
 
 #include <QtMultimedia/qaudio.h>
 #include <QtMultimedia/qaudiodeviceinfo.h>
@@ -116,10 +117,10 @@
     qint64 totalTimeValue;
     bool pullMode;
     int intervalTime;
-    static void CALLBACK waveOutProc( HWAVEOUT hWaveOut, UINT uMsg,
+    static void QT_WIN_CALLBACK waveOutProc( HWAVEOUT hWaveOut, UINT uMsg,
             DWORD dwInstance, DWORD dwParam1, DWORD dwParam2 );
 
-    CRITICAL_SECTION waveOutCriticalSection;
+    QMutex mutex;
 
     WAVEHDR* allocateBlocks(int size, int count);
     void freeBlocks(WAVEHDR* blockArray);