diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index 0d6d32b536..82bf2fadaa 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -17,6 +17,23 @@
    past entries belonging to author(s): Viktor Szakats.
 */
 
+2009-10-31 16:42 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
+  * harbour/contrib/rddads/ads1.c
+    ! In APPEND metohd generate RT error EG_APPENDLOCK only if ACE returns
+      1024 error code (Append Lock Failed). In all other cases generate
+      EG_CORRUPTION RTE.
+      This modifications allows to early detect some serious problems like
+      index corruptions in Mindaugas example with long keys in ADSCDX.
+      Warning! Before ADS RDD generated EG_APPENDLOCK for each errors
+      returned by AdsAppendRecord() and they were caught by default error
+      handler (ERRORSYS) and silently converted to NetErr().
+      Now only for 1024 ACE error which is real append lock error
+      EG_APPENDLOCK is generated and all other errors will not be silently
+      ignored so it's also possible that this modification will exploit
+      some errors in concurrent accessed which are not reported by ADS/ACE
+      as 1024 and maybe we will have to report them as EG_APPENDLOCK too.
+      In such case please send information about such error codes here.
+
 2009-10-31 12:44 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
   * harbour/src/rdd/dbfcdx/dbfcdx1.c
     % added small protection against code which may want to create
diff --git a/harbour/contrib/rddads/ads1.c b/harbour/contrib/rddads/ads1.c
index caa73195e4..894f175a18 100644
--- a/harbour/contrib/rddads/ads1.c
+++ b/harbour/contrib/rddads/ads1.c
@@ -1422,11 +1422,13 @@ static HB_ERRCODE adsAppend( ADSAREAP pArea, BOOL fUnLockAll )
    {
       commonError( pArea, EG_READONLY, EDBF_READONLY, 0, NULL, 0, NULL );
    }
+   else if( u32RetVal == 1024 /* Append Lock Failed */ )
+   {
+      commonError( pArea, EG_APPENDLOCK, EDBF_APPENDLOCK, 0, NULL, EF_CANDEFAULT, NULL );
+   }
    else
    {
-      /* 1001 and 7008 are standard ADS Open Errors that will usually be sharing issues */
-      USHORT uiOsCOde = u32RetVal == 1001 || u32RetVal == 7008 ? 32 : 0;
-      commonError( pArea, EG_APPENDLOCK, ( USHORT ) u32RetVal, uiOsCOde, NULL, EF_CANDEFAULT, NULL );
+      commonError( pArea, EG_CORRUPTION, ( USHORT ) u32RetVal, 0, NULL, EF_CANDEFAULT, NULL );
    }
 
    return HB_FAILURE;