DataSource Controls :: Retrieving SQL Filestream Data With Visual Studio SQLDataSource?

Is there anything special you have to do to retrieve Filestream data using a SqlDataSource? I'm using VB and have this as my sqldatasource:

<asp:SqlDataSource ID="SqlDataSourceReadPD" runat="server" etc...
SelectCommand="SELECT [PDIPAttachment] FROM [PositionDescriptions] WHERE ([CP_IDString] = @CP_IDString)">
<SelectParameters>
<asp:Parameter Name="CP_IDString" Type="String" />
</SelectParameters>
</asp:SqlDataSource>

PDIPAttachment is a FILESTREAM column in my table called PositionDescriptions

and this is some of my VB cod:

Dim dv As DataView = DirectCast(SqlDataSourceReadPD.Select(DataSourceSelectArguments.Empty), DataView)
Dim dr As DataRowView
For Each dr In dv
Dim data as Byte() = System.Text.Encoding.ASCII.GetBytes(dr("PDIPAttachment").ToString())
Next

The Filestream data has a PDF file in it, but what I"m getting back in "data" are 13 bytes consisting of: "System.Byte[]".