You need to close the recordset returned by the command:

DataEnvironment1.rsCommand1.close

>The following code passes a parameter to a Data Report and runs the report.
>
>Private Sub Command1_Click()
> ' Pass datetime stamp to Data Report
> RptKey = Data1.Recordset.Fields("datetime")
> DataEnvironment1.Command1 RptKey
> DataReport1.Show
>End Sub
>
>When I run the above report the first time, it works fine. After running it twice, I receive the following error:
>
> Run-Time error 3705
>
> Operation is not allowed when the object is open
>
>The debugger highlights the DataEnvironment1 line as the error line.
>I am new to Visual Basic - any help would be appreciated.