Combo Box dynamic code not working

guitar713 Again, the majority of the problems you're experiencing are due to the application window being hidden. Setting the RowSource property of a List Box or Combo Box when the workbook is hidden is not as simple as it is when the workbook is visible. In the Reset_Form sub routine, try using the same Worksheet.Range.Address method I outlined in my previous replies, with the optional [External] argument set to True:

Sub Reset_Form()
    Dim irow As Long
    With frmDataEntry
    'assigning rowsource to lstDatabase listbox
        .lstDatabase.ColumnCount = 12
        .lstDatabase.ColumnHeads = True
        .lstDatabase.ColumnWidths = "40,80,80,40,45,70,80,0,0,0,0"

    ' identify the last non-blank row in database sheet
        irow = Sheet1.Range("A" & Sheet1.Rows.Count).End(xlUp).Row
        If irow > 9 Then
            .lstDatabase.RowSource = Sheet1.Range("A9:L" & irow).Address(External:=True)
        Else
            .lstDatabase.RowSource = Sheet1.Range("A9:L9").Address(External:=True)
        End If
    End With
End Sub

Note: I changed the starting row in the above code from 2 to 9 because that's the row in your worksheet where the database starts. Also, some of your headers in row 9 (column A, B and C) have been merged with cells in row 8 (using Merge & Center)... this will have an undesirable affect to the appearance of the List Box, since you've set the ColumnHeads property to True. You should "unmerge" those cells and put the column headers in row 9 only.

You could save yourself a lot of headaches by leaving the workbook visible. The same effect that you're going for could be achieved through alternative means. For example, you could designate a single worksheet to be the "landing page" or "navigation page" when the workbook is opened, and every other worksheet could have their Visible property set to xlSheetVeryHidden (so they cannot be unhidden manually by the user). The "navigation page" worksheet could easily be designed just like your current UserForm1, with a button to launch the frmDataEntry user form. This would allow you to keep the workbook visible while hiding all of the other worksheets. Just a thought...