Page not found with mobile application..   

I have a very simple mobile app that has a text box and object list.
Apps seems to be working OK, however time to time when we try to go
back from details page, it takes to:

The page cannot be found

The page you are looking for might have been removed, had its name
changed, or is temporarily unavailable.

If we start search again, it works OK for few times until dies again.

Following is the code.  Any help with be appreciated.

Imports System.Data
Imports System.Data.Sql
Imports System.Data.SqlClient

Partial Class _Default

    Inherits System.Web.UI.MobileControls.MobilePage
    Private objCnn As New
SqlConnection(System.Configuration.ConfigurationSettings.AppSettings("cnnAMP_DEV"))

    'splits the domain\user and returns the user
    Private Function RequestLogon_User() As String

        Dim LogonId As String() =
Request.ServerVariables("Logon_User").Split("\")
        Return LogonId(1)

    End Function

    'Protected Sub frmMain_Activate(ByVal sender As Object, ByVal e As
System.EventArgs) Handles frmMain.Activate
    '    lblWelcome.Text = "Welcome user: " + RequestLogon_User()
    'End Sub

    Private Function PermissionChecking(ByVal LogonID As String) As
Boolean

        Dim objCmd As SqlCommand = New SqlCommand
        Dim objDR As SqlDataReader
        Dim bln As Boolean

        If Not (objCnn.State = ConnectionState.Open) Then
objCnn.Open() '--dh

        With objCmd
            .CommandText = "Donor_Mobile_CheckPermission_ssp"
            .Connection = objCnn
            .CommandType = CommandType.StoredProcedure
            .Parameters.Add("@LogonId", SqlDbType.VarChar, 100).Value
= RequestLogon_User()
        End With

        objDR =
objCmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection)
        objDR.Read()

        With objDR
            If .HasRows Then
                bln = .GetValue(0)
                'bln = .Item(0) Another way of checking the result.
            End If

        End With

        '--dh
        objDR.Close()
        If Not (objCnn.State = ConnectionState.Closed) Then
objCnn.Close()

        Return bln

    End Function

    Private Sub Donor_Mobile_SearchList_Test_ssp()

        Dim objCmd As New SqlCommand
        Dim objDA As New SqlDataAdapter
        Dim objDS As New DataSet

        If Not (objCnn.State = ConnectionState.Open) Then
objCnn.Open()

        With objCmd
            .CommandText = "Donor_Mobile_SearchList_Test_ssp"
            .Connection = objCnn
            .CommandType = CommandType.StoredProcedure
            .Parameters.Add("@SearchText", SqlDbType.VarChar,
50).Value = txtSearch.Text

            objDA.SelectCommand = objCmd
            objDA.Fill(objDS, RTrim(txtSearch.Text))
        End With

        With objListUser
            .DataSource = objDS
            .TableFields = "LastName;FirstName"
            .DataBind()
        End With

    End Sub

    Protected Sub btnSearch_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles btnSearch.Click

        If Len(txtSearch.Text) > 0 Then

            If PermissionChecking(RequestLogon_User) Then
                Donor_Mobile_SearchList_Test_ssp()

            Else
                Me.ActiveForm = frmDenied

            End If
        End If

    End Sub

    Protected Sub frmMain_Load(ByVal sender As Object, ByVal e As
System.EventArgs) Handles frmMain.Load
        lblWelcome.Text = "Welcome user: " + RequestLogon_User()
    End Sub
End Class

date: Fri, 13 Jun 2008 16:11:30 -0700 (PDT)   author:   unknown