Passing DateTime Parameter to Subreport (Error)

Hi guys,

I have managed to pass a string parameter form the main report to the subreport with no problems, but when i try and use the same method to pass a datetime type, i am issued with the following error messase:

"[rsErrorExecutingSubreport] An error occurred while executing the subreport ‘SubReportName’: The value provided for the report parameter 'MasterDate' is not valid for its type."

I cant see why it work for strings, but not for datetime.  Any suggestions will be very much appreciated