diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index 73b224ad81..a32c12fc46 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -1,3 +1,19 @@
+2001-01-09 16:15 UTC+0100 Ryszard Glab <rglab@imid.med.pl>
+
+    *source/rdd/workarea.c
+        *codeblocks used in SET LOCATE are properly locked/unlocked
+        to prevent deallocation by the GC 
+        (thanks to shashkov@orel.ru)
+        
+    *source/vm/macro.c
+        *fixed bug in hb_macroTextSubst() (result buffer reallocation)
+        (thanks to shashkov@orel.ru)
+        
+    *source/vm/memvars.c
+        *fixed access of uninitialized memvar values
+        (thanks to shashkov@orel.ru)
+    
+
 2001-01-08 17:45 UTC-0800 Ron Pinkas <ron@profit-master.com>
    * source/pp/ppcore.c
      ! Fixed ')' as expression terminator in state STATE_ID_END
diff --git a/harbour/source/rdd/workarea.c b/harbour/source/rdd/workarea.c
index 09b8345438..607c6cd883 100644
--- a/harbour/source/rdd/workarea.c
+++ b/harbour/source/rdd/workarea.c
@@ -852,6 +852,7 @@ ERRCODE hb_waClearLocate( AREAP pArea )
    /* Free all items */
    if( pArea->dbsi.itmCobFor )
    {
+      hb_gcUnlockItem( pArea->dbsi.itmCobFor );
       hb_itemRelease( pArea->dbsi.itmCobFor );
       pArea->dbsi.itmCobFor = NULL;
    }
@@ -862,6 +863,7 @@ ERRCODE hb_waClearLocate( AREAP pArea )
    }
    if( pArea->dbsi.itmCobWhile )
    {
+      hb_gcUnlockItem( pArea->dbsi.itmCobWhile );
       hb_itemRelease( pArea->dbsi.itmCobWhile );
       pArea->dbsi.itmCobWhile = NULL;
    }
@@ -935,13 +937,19 @@ ERRCODE hb_waSetLocate( AREAP pArea, LPDBSCOPEINFO pScopeInfo )
    SELF_CLEARLOCATE( pArea );
 
    if( pScopeInfo->itmCobFor )
+   {
       pArea->dbsi.itmCobFor = hb_itemNew( pScopeInfo->itmCobFor );
+      hb_gcLockItem( pArea->dbsi.itmCobFor );
+   }
 
    if( pScopeInfo->lpstrFor )
       pArea->dbsi.lpstrFor = hb_itemNew( pScopeInfo->lpstrFor );
 
    if( pScopeInfo->itmCobWhile )
+   {
       pArea->dbsi.itmCobWhile = hb_itemNew( pScopeInfo->itmCobWhile );
+      hb_gcLockItem( pArea->dbsi.itmCobWhile );
+   }
 
    if( pScopeInfo->lpstrWhile )
       pArea->dbsi.lpstrWhile = hb_itemNew( pScopeInfo->lpstrWhile );
@@ -970,7 +978,7 @@ ERRCODE hb_waCompile( AREAP pArea, BYTE * pExpr )
    pMacro = hb_macroCompile( ( char * ) pExpr );
    if( pMacro )
    {
-      hb_itemPutPtr( pArea->valResult, ( void * ) pMacro );
+      pArea->valResult = hb_itemPutPtr( pArea->valResult, ( void * ) pMacro );
       return SUCCESS;
    }
    else
diff --git a/harbour/source/vm/macro.c b/harbour/source/vm/macro.c
index 039ee87d59..d030eda903 100644
--- a/harbour/source/vm/macro.c
+++ b/harbour/source/vm/macro.c
@@ -353,8 +353,12 @@ char * hb_macroTextSubst( char * szString, ULONG *pulStringLen )
                   ulResStrLen += ( ulValLen - ulNameLen );
                   if( ulResStrLen > ulResBufLen )
                   {
+                     ULONG ulHead = pHead - szResult;
+                     ULONG ulTail = pTail - szResult;
                      ulResBufLen = ulResStrLen;
                      szResult = ( char * ) hb_xrealloc( szResult, ulResBufLen + 1 );
+                     pHead = szResult + ulHead;
+                     pTail = szResult + ulTail;
                   }
                }
                else
diff --git a/harbour/source/vm/memvars.c b/harbour/source/vm/memvars.c
index 28d4108083..6ba6596643 100644
--- a/harbour/source/vm/memvars.c
+++ b/harbour/source/vm/memvars.c
@@ -107,14 +107,13 @@ void hb_memvarsRelease( void )
 
    if( s_globalTable )
    {
-      while( ulCnt )
+      while( --ulCnt )
       {
          if( s_globalTable[ ulCnt ].counter && s_globalTable[ ulCnt ].hPrevMemvar != ( HB_HANDLE )-1 )
          {
             hb_itemClear( &s_globalTable[ ulCnt ].item );
             s_globalTable[ ulCnt ].counter = 0;
          }
-         --ulCnt;
       }
    }
 }
@@ -271,12 +270,15 @@ void hb_memvarSetPrivatesBase( ULONG ulBase )
    {
       --s_privateStackCnt;
       hVar = s_privateStack[ s_privateStackCnt ]->hMemvar;
-      hOldValue = s_globalTable[ hVar ].hPrevMemvar;
-      hb_memvarValueDecRef( hVar );
-      /*
-      * Restore previous value for variables that were overridden
-      */
-      s_privateStack[ s_privateStackCnt ]->hMemvar = hOldValue;
+      if( hVar )
+      {
+          hOldValue = s_globalTable[ hVar ].hPrevMemvar;
+          hb_memvarValueDecRef( hVar );
+          /*
+          * Restore previous value for variables that were overridden
+          */
+          s_privateStack[ s_privateStackCnt ]->hMemvar = hOldValue;
+      }
    }
    s_privateStackBase = ulBase;
 }
@@ -1506,7 +1508,7 @@ void hb_memvarsIsMemvarRef( void )
    {
       ULONG ulCnt = s_globalLastFree;
 
-      while( ulCnt )
+      while( --ulCnt )
       {
          /* do not check detached variables - for these variables only
           * references from the eval stack are meaningfull for the GC
@@ -1515,7 +1517,6 @@ void hb_memvarsIsMemvarRef( void )
          {
             hb_gcItemRef( &s_globalTable[ ulCnt ].item );
          }
-         --ulCnt;
       }
    }
 }