Dear XK8ER,
try having this code in the Form_Closing event
This hides the form and then cancel the close event, and does the trick :-)
for example:
Private Sub frmMonthlyInvoices_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
Me.Hide() 'Hides the form
e.Cancel = True 'Cancels the form_closing Event
End Sub