74hc595 timing probleem

   forever loop
      do something else, maybe some delay
      clock next data into 595 shift registers
      switch row drivers off
      clock the 595 hold register
      enable row driver
   end loop

for row = 0 to 7
 set & reset portd.X          'de juiste rij aan/uit zetten
  for text = 0 to 25          'max. 25 car. op lichtkrant
   set & reset latchbit       'aan het einde van gewenste text de ingeschoven bits naar de uitgang sturen
    for coloms = 0 to 4       'letter bestaat uit 5 kolomen
     zet data bit klaar       'bit die het schuifreg. ingaat
     set & reset klokbit    
   next kolom
  next text 
next row

  $regfile = "m8def.dat"
$crystal = 4000000                                          'internal crystal cksel(3-0) = 0011
                                                             'fuses
                                                             'let op !! geinverteerd invoeren
Ddrc = &B0000_0111
Portc = &B1111_1000

Dim Masker0 As Byte                                         'select bit for row 0
Dim Masker1 As Byte                                         'select bit for row 1
Dim Masker2 As Byte                                         'select bit for row 2
Dim Masker3 As Byte                                         'select bit for row 3
Dim Masker4 As Byte                                         'select bit for row 4
Dim Masker5 As Byte                                         'select bit for row 5
Dim Masker6 As Byte                                         'select bit for row 6
Dim Masker7 As Byte                                         'select bit for row 7
Dim Lettercolum As Byte
Dim Pointer_alfabet As Byte
Dim Pointer_display_text As Byte
Dim Row As Byte
Dim X As Byte                                               'flag for databit
Dim Columx5 As Byte                                         'to pick up 5 colums from alfabet
Dim Character As Byte                                       'letter wich has to pick up from alfabet
Dim Aa As Byte                                              'temp valeu for translate : display_text ---> alfabet
Dim Cc As Byte                                              'temp valeu for translate : display_text ---> alfabet
Dim Qq As Byte                                              'temp valeu for create databit
Dim Empty_display As Byte


Ddrd = &B1111_1111                                          'portD = output for row drivers


Clockbit Alias Portc.0                                      'pin 11 (on 74hc595) SHcp
Databit Alias Portc.1                                       'pin 14 (on 74hc595) DS
Latchbit Alias Portc.2                                      'pin 12 (on 74hc595) STcp

Masker0 = &B00000001                                        'select bit for row 1
Masker1 = &B00000010                                        'select bit for row 2
Masker2 = &B00000100                                        'select bit for row 3
Masker3 = &B00001000                                        'select bit for row 4
Masker4 = &B00010000                                        'select bit for row 5
Masker5 = &B00100000                                        'select bit for row 6
Masker6 = &B01000000                                        'select bit for row 7
Masker7 = &B10000000                                        'select bit for row 8

Do

For Row = 0 To 7
                                            'control row drivers
   If Row = 0 Then
   Portd = &B0000_0001
   End If
   If Row = 1 Then
   Portd = &B0000_0010
   End If
   If Row = 2 Then
   Portd = &B0000_0100
   End If
   If Row = 3 Then
   Portd = &B0000_1000
   End If
   If Row = 4 Then
   Portd = &B0001_0000
   End If
   If Row = 5 Then
   Portd = &B0010_0000
   End If
   If Row = 6 Then
   Portd = &B0100_0000
   End If
   If Row = 7 Then
   Portd = &B1000_0000
   End If






Restore Display_text
   For Pointer_display_text = 0 To 25                       'read the text from the : display_text
      Cc = Lookup(pointer_display_text , Display_text)
      If Cc = &H00 Then
      Waitms 1
      Set Latchbit                                          'to put bits on outputs 74hc595
      Waitus 1
      Reset Latchbit
      Goto End_text_display

      End If

      Aa = Cc - &H20                                        'transfere to place in alfabet
      Character = Aa * 5


   Restore Alfabet
      For Columx5 = 0 To 4

         Pointer_alfabet = Character + Columx5
         Lettercolum = Lookup(pointer_alfabet , Alfabet)    'pick up letter fonttable (alfabet)

         If Row = 0 Then
         X = Lettercolum And Masker0                        'select bit for row 0
         End If
         If Row = 1 Then
         X = Lettercolum And Masker1                        'select bit for row 1
         End If
         If Row = 2 Then
         X = Lettercolum And Masker2                        'select bit for row 2
         End If
         If Row = 3 Then
         X = Lettercolum And Masker3                        'select bit for row 3
         End If
         If Row = 4 Then
         X = Lettercolum And Masker4                        'select bit for row 4
         End If
         If Row = 5 Then
         X = Lettercolum And Masker5                        'select bit for row 5
         End If
         If Row = 6 Then
         X = Lettercolum And Masker6                        'select bit for row 6
         End If
         If Row = 7 Then
         X = Lettercolum And Masker7                        'select bit for row 7
         End If

         If X = 0 Then                                      'becouse the bit after the masker can be on 8 different places
         Qq = 0
         Else
         Qq = 1
         End If

         Databit = Qq                                       'shift bit to 74hc595
         Set Clockbit
         Waitus 10                                          'shift bit to 74hc595
         Reset Clockbit                                     'shift bit to 74hc595


      Next Columx5

   Next Pointer_display_text
End_text_display:

   For Empty_display = 0 To 159
      Databit = 0
      Set Clockbit
      Waitus 10
      Reset Clockbit

      If Empty_display = 159 Then
      Set Latchbit
      Waitus 10
      Reset Latchbit
      End If
      Waitus 1
   Next Empty_display
                                                    'ontime leds
Next Row

Loop

End

Display_text:

'character 1  !!! DIT ZIJN EIGENLIJK 26 BLOKKEN !!!
Data &H41



Alfabet:

' H41      A    !!! DIT ZIJN EIGENLIJK 58 BLOKKEN !!!
Data &B11111100
Data &B00010010
Data &B00010001
Data &B00010010
Data &B11111100

Do
    Portd = 0                                      'Alle kolommen uitschakelen

Restore Display_text
   For Pointer_display_text = 0 To 25              'read the text from the : display_text
      Cc = Lookup(pointer_display_text , Display_text)
      If Cc = &HFF Then                             'enz...

If Row = 0 Then                                     'Nu een nieuwe kolom activeren
   Portd = &B00000001
   End If
   If Row = 1 Then                                  'enz...