Hi Craig, and thanks for your efforts, my code snippet didn't show it but I actually set the criteria and refresh the report before I do the export and out of desperation I commented the code out and tried the export again and it worked ! the code you haven't seen is below

string selectionformula = string.Format("{0}view_clientinvoices.invoiceid{1} = {2}", "{", "}", InvoiceID);
crystaldoc.RecordSelectionFormula = selectionformula;
crystaldoc.Refresh();

which basically creates a string "{view_clientinvoices.invoiceid} = 1"