My Number Of Records Are Different From Views

Why is it my number of records are different from my view. this are the following code that that i used in my code and in my view.

my code in my program: this code show all the records i know

If iConn.State = ConnectionState.Open Then iConn.Close()
iConn.Open()
Dim rsBills As New Data.DataSet
rsBills = New DataSet
Dim daBills As New SqlDataAdapter
daBills = New SqlDataAdapter
rsBills.Clear()
Dim cmBills As New SqlCommand
cmBills = iConn.CreateCommand ' "Select U_Code, U_Name, U_Level, P_Word From EPassword ",
cmBills.CommandText = "Select OR_no, Billing_mo From dbo.vwBilling Where Month(dbo.vwBilling.Billing_mo)= " & Month(Me.dtto.Value) & " And Year(dbo.vwBilling.Billing_mo) = " & Year(Me.dtto.Value) & " ORDER BY OR_no "

daBills.SelectCommand = cmBills
rsBills.AcceptChanges()
rsBills.Clear()
daBills.Fill(rsBills, "Bills")
Me.DataGridView1.DataSource = Nothing
Me.DataGridView1.DataSource = rsBills.Tables("Bills")

my code in views:

SELECT OR_no, Billing_mo, Account_no, Name, Address, Cno, Pres_read, Mprev_read, Sub_read, Pres2, Prev2, SRead2, Mtr_cons, Amount, NPC, Dmem,
Cmem, Tot_bill, D_Pmnt, Class, Newbill, Prd_fr, Prd_to, Type_Pmnt, Type_Date, Type_Docs, wtax
FROM dbo.Billing


hope you can help me guys