--- ../asterisk-1.8.5-clean/main/channel.c	2011-06-30 10:48:47.000000000 +0200
+++ main/channel.c	2011-06-30 07:28:37.000000000 +0200
@@ -4870,6 +4870,10 @@
 			apply_plc(chan, fr);
 		}
 
+		if ((!(fr->subclass.codec & chan->nativeformats)) && (chan->writeformat != fr->subclass.codec)) {
+			ast_set_write_format(chan, fr->subclass.codec);
+		}
+
 		/* If the frame is in the raw write format, then it's easy... just use the frame - otherwise we will have to translate */
 		if (fr->subclass.codec == chan->rawwriteformat)
 			f = fr;