Crystal Reports - Exception - Attempted to Read/Write Protected Memory

[CIMStu]

Hi,

I have resolved my Excel Filetype problem thanks to help from here!

Unfortunately i am now getting an unhandled exception error which i can't get my head around.

I am using Crystal Reports 9 Viewer to open a report i have created in Crystal Reports, which uses the data in the Excel document created, and some from another database.

If i run my code, and set my report datasource to a Blank report, it opens fine, if i set it to a report that only references the other database, it loads fine.

As soon as i try to open the report i want, which references my excel spreadsheets, i get a exception "Attempted to read or write protected memory. This is often an indication that other memory is corrupt."

My Code is below

Dim crApp As CRAXDRT.Application
        Dim oForm As New frmCrystal
        Dim mvarFileName As String

        Me.Cursor = Cursors.WaitCursor

        mvarFileName = "C:\Program Files\CIM\Trial_Kitting.rpt"
        crApp = New CRAXDRT.Application
        oReport = crApp.OpenReport(mvarFileName, 1)
        With oReport
            .VerifyOnEveryPrint = False
            .MorePrintEngineErrorMessages = False
            .PrintDate = Now
            '            .PaperOrientation = CRAXDRT.CRPaperOrientation.crLandscape
            .DiscardSavedData()
        End With

        oForm.Text = "Crystal Reports - Multiple Trial Kitting"
        oForm.AxCRViewer91.ReportSource = oReport
        oForm.AxCRViewer91.Zoom(1)
        oForm.AxCRViewer91.ViewReport()

        Me.Cursor = Cursors.Default
        Application.DoEvents()

        oForm.ShowDialog()

        oForm = Nothing
        oReport = Nothing
        crApp = Nothing
        mvarFileName = Nothing

The line that triggers the exception is the Application.DoEvents.
If i remove that line the exception occurs and doesn't indicate which line is throwing the exception.

I have googled the error and read up the help files and alot of information i've read refers to unmanaged com components and cross threading. Something i have heard of but have no understanding of beyond that. D'oh!!

Any help appreciated