Databound dropdownlist inside a repeater

Hi

I have a databound dropdownlist and use OnItemDataBound to pre-select IMF Types that are stored in my database.  This
approach works fine when there are IMF Type records to show in the repeater but when there are no records I get the error message
"Conversion from type 'DBNull' to type 'String' is not valid"

Protected Sub rptIMFTypes_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.RepeaterItemEventArgs)
        Dim ddlIMFTypes As DropDownList = e.Item.FindControl("ddlIMFTypes")
        If Not e.Item.FindControl("ddlIMFTypes") Is Nothing Then
            ddlIMFTypes.Items.FindByValue(CType(System.Web.UI.DataBinder.Eval(e.Item.DataItem, "IMF_ID"), Object)).Selected = True
        End If
End Sub

<asp:Repeater id="rptIMFTypes" runat="server" OnItemDataBound="rptIMFTypes_ItemDataBound">
      <HeaderTemplate>
         <table cellpadding="3" cellspacing="1" border="0">                             
      </HeaderTemplate>
      <ItemTemplate>                  
             <tr>
               <td>
               <asp:DropDownList id="ddlIMFTypes" Runat="Server"
                    DataSourceID="dsIMFTypes"
                    DataTextField="IMF_Type"
                    DataValueField="IMF_ID"
                    CssClass="formLabel" />
               </td>              
            </tr>
      </ItemTemplate>
      <FooterTemplate>            
          </table>    
      </FooterTemplate>
   </asp:Repeater>

I also tried this but it didn't work

If IsDBNull(CType(System.Web.UI.DataBinder.Eval(e.Item.DataItem, "IMF_ID"), Object) = False) Then