Index: main/frame.c
===================================================================
--- main/frame.c	(revision 244242)
+++ main/frame.c	(working copy)
@@ -300,6 +300,10 @@
 	if ((frames = ast_threadstorage_get(&frame_cache, sizeof(*frames)))) {
 		if ((f = AST_LIST_REMOVE_HEAD(&frames->list, frame_list))) {
 			size_t mallocd_len = f->mallocd_hdr_len;
+			if (f->samples != -1) {
+				ast_log(LOG_ERROR, "Used frame in free list! Tossing.\n");
+				return ast_frame_header_new();
+			}
 			memset(f, 0, sizeof(*f));
 			f->mallocd_hdr_len = mallocd_len;
 			f->mallocd = AST_MALLOCD_HDR;
@@ -325,9 +329,14 @@
 	struct ast_frame_cache *frames = data;
 	struct ast_frame *f;
 
-	while ((f = AST_LIST_REMOVE_HEAD(&frames->list, frame_list)))
+	while ((f = AST_LIST_REMOVE_HEAD(&frames->list, frame_list))) {
+		if (f->samples != -1) {
+			ast_log(LOG_ERROR, "Used frame in free list! Not free'ing\n");
+			continue;
+		}
 		ast_free(f);
-	
+	}
+
 	ast_free(frames);
 }
 #endif
@@ -345,7 +354,13 @@
 
 		if ((frames = ast_threadstorage_get(&frame_cache, sizeof(*frames))) &&
 		    (frames->size < FRAME_CACHE_MAX_SIZE)) {
+			if (fr->samples == -1) {
+				ast_log(LOG_ERROR, "Frame already freed! Not storing.\n");
+				ast_backtrace();
+				return;
+			}
 			AST_LIST_INSERT_HEAD(&frames->list, fr, frame_list);
+			fr->samples = -1;
 			frames->size++;
 			return;
 		}
@@ -490,6 +505,11 @@
 #if !defined(LOW_MEMORY)
 	if ((frames = ast_threadstorage_get(&frame_cache, sizeof(*frames)))) {
 		AST_LIST_TRAVERSE_SAFE_BEGIN(&frames->list, out, frame_list) {
+			if (out->samples != -1) {
+				ast_log(LOG_ERROR, "Used frame in free list!\n");
+				continue;
+			}
+
 			if (out->mallocd_hdr_len >= len) {
 				size_t mallocd_len = out->mallocd_hdr_len;