diff --git a/binlog.c b/binlog.c
index 62382db..df30269 100644
--- a/binlog.c
+++ b/binlog.c
@@ -1,6 +1,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/file.h>
 #include <stdlib.h>
 #include <fcntl.h>
 #include <errno.h>
@@ -1024,7 +1025,7 @@ void replay_log_event (void) {
     rptr = in_ptr;
     break;
   default:
-    logprintf ("Unknown logevent [0x%08x] 0x%08x [0x%08x]\n", *(rptr - 1), op, *(rptr + 1));
+    logprintf ("Unknown logevent [0x%08x] 0x%08x [0x%08x] at %lld\n", *(rptr - 1), op, *(rptr + 1), binlog_pos);
 
     assert (0);
   }
@@ -1075,8 +1076,8 @@ void replay_log (void) {
       } else {
         int x = wptr - rptr;
         memcpy (binlog_buffer, rptr, 4 * x);
-        wptr -= x;
-        rptr -= x;
+        wptr -= (rptr - binlog_buffer);
+        rptr = binlog_buffer;
       }
       int l = (binlog_buffer + BINLOG_BUFFER_SIZE - wptr) * 4;
       int k = read (fd, wptr, l);
@@ -1103,7 +1104,12 @@ void write_binlog (void) {
     perror ("binlog open");
     exit (2);
   }
-  lseek (binlog_fd, 0, SEEK_END);
+  
+  assert (lseek (binlog_fd, binlog_pos, SEEK_SET) == binlog_pos);
+  if (flock (binlog_fd, LOCK_EX | LOCK_NB) < 0) {
+    perror ("get lock");
+    exit (2);
+  } 
 }
 
 void add_log_event (const int *data, int len) {
diff --git a/config.sample b/config.sample
index 588090f..dffcc44 100644
--- a/config.sample
+++ b/config.sample
@@ -1,22 +1,66 @@
-# This is my real config
-# Feel free to edit it
+# This is an empty config file
+# Feel free to put something here
 
-default_profile = "tele2";
+default_profile = "binlog";
 
-mts = {
+test_dc1 = {
+  config_directory = ".telegram/test_dc1";
+  test = true;
+  msg_num = true;
+  binlog_enabled = true;
+};
+
+binlog = {
+  config_directory = ".telegram/binlog";
+  test = false;
+  msg_num = true;
+  binlog_enabled = true;
+  log_level = 2;
+};
+
+binlog_mts = {
+  config_directory = ".telegram/binlog_mts";
+  test = false;
+  msg_num = true;
+  binlog_enabled = true;
+  log_level = 2;
+};
+
+mega = {
+  config_directory = ".telegram/mega";
+  test = false;
+  msg_num = true;
+  binlog_enabled = true;
+  log_level = 2;
+};
+
+new = {
+  config_directory = ".telegram/new";
   test = false;
-  config_directory = ".telegram/mts";
   msg_num = true;
 };
 
-tele2 = {
+production = {
+  config_directory = ".telegram/production";
   test = false;
-  config_directory = ".telegram/tele2";
   msg_num = true;
 };
 
 test = {
-  test = true;
   config_directory = ".telegram/test";
+  test = true;
   msg_num = true;
 };
+
+test1 = {
+  config_directory = ".telegram/test1";
+  msg_num = true;
+  binlog_enabled = true;
+};
+
+test2 = {
+  config_directory = ".telegram/test2";
+  msg_num = true;
+  binlog_enabled = true;
+};
+
diff --git a/main.c b/main.c
index 3d9c4a1..10fc3be 100644
--- a/main.c
+++ b/main.c
@@ -77,6 +77,7 @@ char *config_directory;
 char *binlog_file_name;
 int binlog_enabled;
 extern int log_level;
+int sync_from_start;
 
 void set_default_username (const char *s) {
   if (default_username) { 
@@ -315,7 +316,7 @@ extern int default_dc_num;
 int register_mode;
 void args_parse (int argc, char **argv) {
   int opt = 0;
-  while ((opt = getopt (argc, argv, "u:hk:vn:Nc:p:l:R")) != -1) {
+  while ((opt = getopt (argc, argv, "u:hk:vn:Nc:p:l:Rf")) != -1) {
     switch (opt) {
     case 'u':
       set_default_username (optarg);
@@ -342,6 +343,9 @@ void args_parse (int argc, char **argv) {
     case 'R':
       register_mode = 1;
       break;
+    case 'f':
+      sync_from_start = 1;
+      break;
     case 'h':
     default:
       usage ();
diff --git a/queries.c b/queries.c
index bd4aaf8..64351d9 100644
--- a/queries.c
+++ b/queries.c
@@ -64,6 +64,7 @@ long long cur_downloading_bytes;
 long long cur_downloaded_bytes;
 
 extern int binlog_enabled;
+extern int sync_from_start;
 
 void out_peer_id (peer_id_t id);
 #define QUERY_TIMEOUT 6.0
@@ -2218,6 +2219,14 @@ BN_CTX *ctx;
 
 void do_send_accept_encr_chat (struct secret_chat *E, unsigned char *random) {
   int i;
+  int ok = 0;
+  for (i = 0; i < 64; i++) {
+    if (E->key[i]) {
+      ok = 1;
+      break;
+    }
+  }
+  if (ok) { return; } // Already generated key for this chat
   for (i = 0; i < 64; i++) {
     *(((int *)random) + i) ^= mrand48 ();
   }
@@ -2521,7 +2530,10 @@ void do_get_difference (void) {
   difference_got = 0;
   clear_packet ();
   do_insert_header ();
-  if (seq > 0) {
+  if (seq > 0 || sync_from_start) {
+    if (pts == 0) { pts = 1; }
+    if (qts == 0) { qts = 1; }
+    if (last_date == 0) { last_date = 1; }
     out_int (CODE_updates_get_difference);
     out_int (pts);
     out_int (last_date);