F4 not showing header?

Hi Guys,

I manage to create a F4 for my parameter in Screen 100. However, 1 of the field name's header is not showing. Any ideas? I've checked the data element..the descriptions are all there.....Hope you gurus can help me on this. Thanks! Points will be awarded 😊

  SELECT MATNR WERKS ZSC_ARBPL
        INTO TABLE I_MATNR
        FROM Z_CUSTOM_MATNR.

  CALL FUNCTION 'F4IF_INT_TABLE_VALUE_REQUEST'
    EXPORTING
      RETFIELD     = 'MATNR'
      DYNPPROG     = SY-CPROG
      DYNPNR       = SY-DYNNR
      DYNPROFIELD  = 'P_MATNR'
      WINDOW_TITLE = 'Material'
      VALUE_ORG    = 'S'
      DISPLAY      = 'F'
    TABLES
      VALUE_TAB    = I_MATNR.

Here is the screen shot of the F4 popup result

Screen" target="_blank">http://img483.imageshack.us/img483/8234/screenshot1ro8.jpg">Screen Shot1