I am trying to make some controls in a custom module visible only to users in the "Administrators" role. To do so, I am using the following code:

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
        If DotNetNuke.Security.PortalSecurity.IsInRole("Administrators") Then
            GridView1.Columns(0).Visible = True
        Else
            GridView1.Columns(0).Visible = False
        End If
    End Sub

The problem I am having is that the If...Then block evaluates to True no matter what. Even if I change the string in the IsInRole function to "Goober" (which is not a real Role) it still evaluates to True and the GridView1 column is visible.

Is this the correct way to set the Visibility of controls based upon the logged-in user's Role, or is there another way?