No value given for one or more required parameters. - Record Set Selection Statement

Here is an Clip of the code that I am using:

cnt.Open("Provider=Microsoft.Jet.OLEDB.4.0;" & _
                                                       "Data Source=H:\Custom\edwards\INV2002.mdb")

        rst.CursorType = ADODB.CursorTypeEnum.adOpenStatic

        InvStart = TextBox1.Text
        InvFinish = TextBox2.Text

        rst.open("SELECT InvoiceHeader.InvoiceNumber, InvoiceHeader.CustomerID, InvoiceHeader.SONumber, SOHeader.CustomerPO, InvoiceHeader.ShipmentDate,ShipViaCodes.DescText, FOBCodes.DescText AS Expr1 FROM(((InvoiceHeader INNER JOIN SOHeader ON InvoiceHeader.SONumber = SOHeader.SONumber) INNER JOIN ShipViaCodes ON SOHeader.ShipViaCode = ShipViaCodes.ShipViaCode) INNER JOIN FOBCodes ON SOHeader.FOBCode = FOBCodes.FOBCode) WHERE (InvoiceHeader.InvoiceNumber >= InvStart) AND (InvoiceHeader.InvoiceNumber <= InvFinish)ORDER BY InvoiceHeader.InvoiceNumber", cnt)

In Textbox1 I have: IN03 00003 and In Textbox2 I have: IN03 00006

If I put the exact values in
WHERE (InvoiceHeader.InvoiceNumber >=  'IN03 00003') and (InvoiceHeader.InvoiceNumber <=  'IN03 00006')
It Works

But If I want it to pull the values from my text boxes it says
No value given for one or more required parameters.

If pull up a watch window and I put a watch on InvStart and InvFinish they contain the proper values.

Any Ideas????