diff -r 79de32ba3296 -r 89e065397ea6 src/multimedia/audio/qaudiooutput_win32_p.h
--- a/src/multimedia/audio/qaudiooutput_win32_p.h	Fri May 14 16:40:13 2010 +0300
+++ b/src/multimedia/audio/qaudiooutput_win32_p.h	Thu May 27 13:40:48 2010 +0300
@@ -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>
@@ -119,7 +120,7 @@
     static void 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);