Index: code/client/snd_openal.c
===================================================================
--- code/client/snd_openal.c	(revision 803)
+++ code/client/snd_openal.c	(working copy)
@@ -1495,6 +1495,8 @@
 	{
 		ALuint b;
 		qalSourceUnqueueBuffers(musicSource, 1, &b);
+		if( !b )
+			continue;
 		S_AL_MusicProcess(b);
 		qalSourceQueueBuffers(musicSource, 1, &b);
 	}