Index: main/channel.c
===================================================================
--- main/channel.c	(revision 119891)
+++ main/channel.c	(working copy)
@@ -2172,7 +2172,14 @@
 					ast_log(LOG_DTMF, "DTMF end '%c' has duration %ld but want minimum %d, emulating on %s\n", f->subclass, f->len, AST_MIN_DTMF_DURATION, chan->name);
 					ast_set_flag(chan, AST_FLAG_EMULATE_DTMF);
 					chan->emulate_dtmf_digit = f->subclass;
-					chan->emulate_dtmf_duration = AST_MIN_DTMF_DURATION - f->len;
+				        // instead of shortening the min duration,
+				        // set the start time in the past, this will
+				        // result in more accurate dtmf values
+				        chan->emulate_dtmf_duration = AST_MIN_DTMF_DURATION;
+				         // in DTMF_END_ONLY we don't set the start
+				         // so we need to do it now
+				         chan->dtmf_tv = ast_tvsub(now, ast_tv(0, f->len*1000));
+				         
 					ast_frfree(f);
 					f = &ast_null_frame;
 				} else {