Index: /trunk/src/VBox/Devices/Audio/DrvAudio.cpp
===================================================================
--- /trunk/src/VBox/Devices/Audio/DrvAudio.cpp	(revision 64865)
+++ /trunk/src/VBox/Devices/Audio/DrvAudio.cpp	(revision 64866)
@@ -768,5 +768,5 @@
     AssertPtrReturn(pStream,    VERR_INVALID_POINTER);
     AssertPtrReturn(pvBuf,      VERR_INVALID_POINTER);
-    AssertReturn(cbBuf,         VERR_INVALID_POINTER);
+    AssertReturn(cbBuf,         VERR_INVALID_PARAMETER);
     /* pcbWritten is optional. */
 
@@ -805,4 +805,5 @@
 
         PPDMAUDIOSTREAM pGstStream = pHstStream->pPair;
+        AssertPtr(pGstStream);
 
         AssertMsg(pGstStream->fStatus & PDMAUDIOSTRMSTS_FLAG_ENABLED,
@@ -815,5 +816,5 @@
             LogRel2(("Audio: Guest stream '%s' full, expect stuttering audio output\n", pGstStream->szName));
 #ifdef DEBUG_andy
-            AssertMsgFailed(("%s: Guest stream full\n", pGstStream->szName));
+            AssertMsgFailed(("%s: Guest stream full: cbBuf=%RU32\n", pGstStream->szName, cbBuf));
 #endif
             break;
@@ -848,5 +849,5 @@
             {
                 LogRel2(("Audio: Lost audio samples (%RU32) due to full host stream '%s', expect stuttering audio output\n",
-                         csWritten - csMixed, pGstStream->szName));
+                         csWritten - csMixed, pHstStream->szName));
             }