I think I am using 9.0, so I don't know if this applies for you. Here is what I started with, and it worked well.
Code:
    'Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    '    If Not Page.IsPostBack Then
    '        'Put user code to initialize the page here
    '        Dim dsTemp As New ApplicationDS
    '        Dim myReport As New CrystalReport1


    '        SqlDataAdapter1.Fill(dsTemp)

    '        myReport.SetDataSource(dsTemp)
    '        CrystalReportViewer1.ReportSource = myReport
    '    End If


    'End Sub

    'Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    '    Dim myExportOptions As CrystalDecisions.Shared.ExportOptions
    '    Dim myDiskFileDestinationOptions As CrystalDecisions.Shared.DiskFileDestinationOptions

    '    Dim strExportFile As String
    '    Dim myReport As New CrystalReport1
    '    Dim dsTemp As New ApplicationDS

    '    SqlDataAdapter1.Fill(dsTemp)

    '    myReport.SetDataSource(dsTemp)

    '    strExportFile = "C:\Reports\" & Session.SessionID.ToString() & ".pdf"

    '    myDiskFileDestinationOptions = New CrystalDecisions.Shared.DiskFileDestinationOptions
    '    myDiskFileDestinationOptions.DiskFileName = strExportFile

    '    myExportOptions = myReport.ExportOptions
    '    With myExportOptions
    '        .DestinationOptions = myDiskFileDestinationOptions
    '        .ExportDestinationType = .ExportDestinationType.DiskFile
    '        .ExportFormatType = .ExportFormatType.PortableDocFormat
    '    End With

    '    myReport.Export()
    '    '        myReport.ExportToDisk(CrystalDecisions.[Shared].ExportFormatType.PortableDocFormat, strExportFile)

    '    Response.ClearContent()
    '    Response.ClearHeaders()
    '    Response.ContentType = "application/pdf"
    '    Response.WriteFile(strExportFile)
    '    Response.Flush()
    '    Response.Close()
    '    System.IO.File.Delete(strExportFile)

    'End Sub