Index: apps/app_queue.c
===================================================================
--- apps/app_queue.c	(revision 83022)
+++ apps/app_queue.c	(working copy)
@@ -2883,8 +2883,16 @@
 						
 					ast_debug(1, "Arguments being passed to MixMonitor: %s\n", mixmonargs);
 
+					/* prevent update of lastapp and lastdata in pbx_exec */
+					if (qe->chan->cdr) 
+						ast_set_flag(qe->chan->cdr, AST_CDR_FLAG_LOCKED);
+
 					ret = pbx_exec(qe->chan, mixmonapp, mixmonargs);
 
+					/* clear 'locked' flag after pbx_exec */
+					if (qe->chan->cdr) 
+						ast_clear_flag(qe->chan->cdr, AST_CDR_FLAG_LOCKED);
+
 				} else
 					ast_log(LOG_WARNING, "Asked to run MixMonitor on this call, but cannot find the MixMonitor app!\n");