--- ../asterisk-1.6.1.0/channels/chan_sip.c	2009-04-20 21:08:26.000000000 +0400
+++ asterisk-1.6.1.0/channels/chan_sip.c	2009-06-23 00:45:01.000000000 +0400
@@ -8769,12 +8769,17 @@
 		   Note that p->prefcodec can include video codecs, so mask them out
 		*/
 		if (capability & p->prefcodec) {
-			int codec = p->prefcodec & AST_FORMAT_AUDIO_MASK;
-
-			add_codec_to_sdp(p, codec, SDP_SAMPLE_RATE(codec),
-					 &m_audio, &a_audio,
-					 debug, &min_audio_packet_size);
-			alreadysent |= codec;
+			int mask;
+			for (mask = 1; mask < AST_FORMAT_AUDIO_MASK; mask <<= 1) {
+				int codec = p->prefcodec & mask;
+				if (codec) {
+					add_codec_to_sdp(p, codec, SDP_SAMPLE_RATE(codec),
+					 		&m_audio, &a_audio,
+					 		debug, &min_audio_packet_size);
+					alreadysent |= codec;
+					break;
+				}
+			}
 		}
 
 		/* Start by sending our preferred audio/video codecs */