diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index 67209b0899..2bf57af3db 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -16,6 +16,14 @@
    The license applies to all entries newer than 2009-04-28.
 */
 
+2011-01-30 00:21 UTC+0100 Viktor Szakats (harbour.01 syenar.hu)
+  * src/rtl/listbox.prg
+    ! _LISTBOX_(): Fixed very old bug (can't access ViewVC ATM, but around ~r7550)
+      causing incompatibility with C5.3 regarding IsOpen initial value. It was
+      wrongly initialized by parameter what is now correctly renamed to lScrollBar.
+      Was wrongly named lIsOpen before this fix.
+    % Don't pass default style value to ScrollBar()
+
 2011-01-29 20:29 UTC+0100 Viktor Szakats (harbour.01 syenar.hu)
   * utils/hbmk2/hbmk2.prg
   * utils/hbmk2/hbmk2.*.po
diff --git a/harbour/src/rtl/listbox.prg b/harbour/src/rtl/listbox.prg
index f691c65af5..5c2cbcfdff 100644
--- a/harbour/src/rtl/listbox.prg
+++ b/harbour/src/rtl/listbox.prg
@@ -1095,7 +1095,7 @@ FUNCTION ListBox( nTop, nLeft, nBottom, nRight, lDropDown )
    RETURN HBListBox():New( nTop, nLeft, nBottom, nRight, lDropDown )
 
 FUNCTION _LISTBOX_( nTop, nLeft, nBottom, nRight, xPos, aItems, cCaption,;
-                    cMessage, cColorSpec, bFBlock, bSBlock, lDropDown, lIsOpen, cBitmap )
+                    cMessage, cColorSpec, bFBlock, bSBlock, lDropDown, lScrollBar, cBitmap )
 
    LOCAL o := HBListBox():New( nTop, nLeft, nBottom, nRight, lDropDown )
 
@@ -1114,7 +1114,6 @@ FUNCTION _LISTBOX_( nTop, nLeft, nBottom, nRight, xPos, aItems, cCaption,;
       o:message   := cMessage
       o:fBlock    := bFBlock
       o:sBlock    := bSBlock
-      o:isOpen    := lIsOpen
 
       nLen := Len( aItems )
       FOR nPos := 1 TO nLen
@@ -1130,11 +1129,11 @@ FUNCTION _LISTBOX_( nTop, nLeft, nBottom, nRight, xPos, aItems, cCaption,;
          ENDIF
       NEXT
 
-      IF ISLOGICAL( lIsOpen ) .AND. lIsOpen
+      IF ISLOGICAL( lScrollBar ) .AND. lScrollBar
          IF ISLOGICAL( lDropDown ) .AND. lDropDown
             nTop++
          ENDIF
-         o:VScroll := ScrollBar( nTop + 1, nBottom - 1, nRight,, SCROLL_VERTICAL )
+         o:VScroll := ScrollBar( nTop + 1, nBottom - 1, nRight )
       ENDIF
 
       IF ISCHARACTER( cBitmap )