The following code extracts text to a listbox based on a find routine.
If I try to extract further information off another sheet based on the
"find" of the the first search it complains with an error code 91. The
additional code is between the '===========
What am I doing wrong?

Sub Fill_Task_TextBox()
GroupNumber = Cells(ActiveCell.Row, 10).Value
With Sheets("Tasks").Range("A3:A" & Sheets("Tasks").Range
_("A65530").EndxlUp).Row)
Set Task_Group = .Find(GroupNumber, lookin:=xlValues)
If Not Task_Group Is Nothing Then
Tasks.ListBox1.Clear
FirstAddress = Task_Group.Address
Tasks.ListBox1.AddItem Task_Group.Value & " __ " & _
ActiveCell(0, -1).Value & " __ " & ActiveCell.Value
Tasks.ListBox1.AddItem
Do
Tasks.ListBox1.AddItem Task_Group.Offset(0, 1).Value & _
"-- " & Task_Group.Offset(0, 6).Value

' =============================================== Extra
search Start
If Len(Task_Group.Offset(0, 8).Value) 4 Then
Std_txt_Number = Left(Task_Group.Offset(0, 8).Value, 6)
With Sheets("Std_txt").Range("A3:A" & _
Sheets("Std_txt").Range("A65530").End(xlUp).Row)
Set Stdtxt = .Find(Std_txt_Number, lookin:=xlValues)
If Not Stdtxt Is Nothing Then
Tasks.ListBox1.AddItem Stdtxt.Offset(0,
2).Value
End If
End With
End If
' =============================================== Extra
Search Stop

Set Task_Group = .FindNext(Task_Group)
Loop While Not Task_Group Is Nothing And _
Task_Group.Address < FirstAddress ' get error 91 on
this line?
End If
Tasks.ListBox1.AddItem ""
Tasks.Show
End With

End Sub