diff --git a/firmware/target/hosted/android/pcm-android.c b/firmware/target/hosted/android/pcm-android.c
index ae8e9a2..5a9721c 100644
--- a/firmware/target/hosted/android/pcm-android.c
+++ b/firmware/target/hosted/android/pcm-android.c
@@ -5,7 +5,7 @@
  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
  *                     \/            \/     \/    \/            \/
- * $Id$
+ * $Id: pcm-android.c 29826 2011-05-05 19:20:58Z bluebrother $
  *
  * Copyright (c) 2010 Thomas Martitz
  *
@@ -23,6 +23,7 @@
 #include <stdbool.h>
 #define _SYSTEM_WITH_JNI /* for getJavaEnvironment */
 #include <system.h>
+#include <pthread.h>
 #include "debug.h"
 #include "pcm.h"

@@ -31,6 +32,8 @@ extern JNIEnv *env_ptr;
 /* infos about our pcm chunks */
 static size_t  pcm_data_size;
 static char   *pcm_data_start;
+static int     audio_locked = 0;
+static pthread_mutex_t audio_lock_mutex = PTHREAD_MUTEX_INITIALIZER;

 /* cache frequently called methods */
 static jmethodID play_pause_method;
@@ -41,6 +44,20 @@ static jobject   RockboxPCM_instance;


 /*
+ * mutex lock/unlock wrappers neatness' sake
+ */
+static inline void lock_audio(void)
+{
+    pthread_mutex_lock(&audio_lock_mutex);
+}
+
+static inline void unlock_audio(void)
+{
+    pthread_mutex_unlock(&audio_lock_mutex);
+}
+
+
+/*
  * transfer our raw data into a java array
  *
  * a bit of a monster functions, but it should cover all cases to overcome
@@ -57,6 +74,8 @@ Java_org_rockbox_RockboxPCM_pcmSamplesToByteArray(JNIEnv *env,
                                                   jobject this,
                                                   jbyteArray arr)
 {
+    lock_audio();
+
     (void)this;
     size_t len;
     size_t array_size = (*env)->GetArrayLength(env, arr);
@@ -76,6 +95,7 @@ Java_org_rockbox_RockboxPCM_pcmSamplesToByteArray(JNIEnv *env,
         if (pcm_data_size == 0)
         {
             DEBUGF("out of data\n");
+            unlock_audio();
             return;
         }
         if (remaining > pcm_data_size)
@@ -90,19 +110,26 @@ Java_org_rockbox_RockboxPCM_pcmSamplesToByteArray(JNIEnv *env,
             goto retry;
         }
         else
+        {
             (*env)->SetByteArrayRegion(env, arr, offset, remaining, pcm_data_start);
+        }
         len = remaining;
     }
     pcm_data_start += len;
     pcm_data_size -= len;
+    unlock_audio();
 }

 void pcm_play_lock(void)
 {
+    if (++audio_locked == 1)
+        lock_audio();
 }

 void pcm_play_unlock(void)
 {
+    if (--audio_locked == 0);
+        unlock_audio();
 }

 void pcm_dma_apply_settings(void)
@@ -168,8 +195,6 @@ void pcm_play_dma_init(void)
     play_pause_method = e->GetMethodID(env_ptr, RockboxPCM_class, "play_pause", "(Z)V");
     set_volume_method = e->GetMethodID(env_ptr, RockboxPCM_class, "set_volume", "(I)V");
     stop_method       = e->GetMethodID(env_ptr, RockboxPCM_class, "stop", "()V");
-    /* get initial pcm data, if any */
-    pcm_play_get_more_callback((void*)&pcm_data_start, &pcm_data_size);
 }

 void pcm_postinit(void)