DacPagedDatastore might crash with a runtime error when used in a
quickbrowse when scrolling up under certain circumstances.

Case 1: QBROWSE1 sample from the source\samples\basics\qbrowse folder:
- Start sample
- press CTRL-PGDN
- hold UP key pressed
- "Error in array index" occurs

Case 2: QBROWSE2 sample from the source\samples\basics\qbrowse folder:
- Start sample
- a) Type in number 22 (pointer moves to last row, and only
     last row is displayed)
  b) Move about half page down, select 1st wisible row,
- Maximize window
- Try to move up (with scroll bar, wheel, keyborad ...)
  "Error in array index" occurs

Problem has been solved. Download the fix here. This issue does not
exist in future versions.

If this is not applicable, try the following:

As a workaround, use this class instead of the built in DacPagedDatastore
class:

#define WA4634
#ifdef WA4634

// overloaded PDS class to fix PDR 4634
CLASS MyDacPagedDatastore FROM DacPagedDatastore
EXPORTED:
   INLINE METHOD ScrollRowBuffer( nDirection )
      LOCAL nRow := ::aRowData[::nCurrRow][1]
      LOCAL xRet := ::dacPagedDatastore:ScrollRowBuffer( nDirection )
      LOCAL oCurrentConsumer := ::oConsumer
      IF ::nCurrRow == 0
        ::nCurrRow := nRow + nDirection
        ::oConsumer := NIL
        ::refresh()
        ::oConsumer := oCurrentConsumer
      ENDIF
   RETURN xRet
ENDCLASS

#endif