Vb Data Reports

Sir,
When I try to execute the report for 1 st time this procedure works fine,

Private Sub DataReport_Initialize()
If DataEnvironment1.rsList_Grp.Requery Then
DataEnvironment1.rsList_Grp.Requery
DataEnvironment1.rsList_Grp.Filter = "Name='" & gsUserR & "'"
End If
End Sub

But when I try to execute this for the second time. It is raising the following error in the filter statement.
DataEnvironment1.rsList_Grp.Filter = "Name='" & gsUserR & "'"

run time error 3001

The application is using arguments that are of the wrong type, are out of acceptable range, or are in conflict with one another.

please help me to over come this problem.