--- clean/asterisk-1.4.4/main/app.c	2007-04-25 21:21:54.000000000 +0200
+++ asterisk-1.4.4/main/app.c	2007-05-15 20:40:28.000000000 +0200
@@ -806,12 +806,16 @@
 		len += strlen(category) + 1;
 	
 	AST_LIST_LOCK(&groups);
-	AST_LIST_TRAVERSE(&groups, gi, list) {
-		if (gi->chan == chan && !strcasecmp(gi->group, group) && (ast_strlen_zero(category) || (!ast_strlen_zero(gi->category) && !strcasecmp(gi->category, category))))
+	AST_LIST_TRAVERSE_SAFE_BEGIN(&groups, gi, list) {
+		if ((gi->chan == chan) && ((ast_strlen_zero(category) && ast_strlen_zero(gi->category)) || (!ast_strlen_zero(gi->category) && !strcasecmp(gi->category, category)))) {
+			AST_LIST_REMOVE_CURRENT(&groups, list);
+			free(gi);
 			break;
+		}
 	}
-	
-	if (!gi && (gi = calloc(1, len))) {
+	AST_LIST_TRAVERSE_SAFE_END;
+		
+	if ((gi = calloc(1, len))) {
 		gi->chan = chan;
 		gi->group = (char *) gi + sizeof(*gi);
 		strcpy(gi->group, group);