Intermitten Paging Error

Hello all,

 I am having an intermitten paging problem and can't figure out why.  It doesn't happen each time but quite often.  I am using the default allow paging text box filing the data set with a simple query.  And when you start at 1 and work your way up through the pages, it will throw this error page on the screen and will not go further.  Usually happens in the mid 20'2 to 30's page.  Any Ideas?

 
The resource cannot be found.

Description: HTTP 404. The resource you are looking for (or one of its dependencies) could have been removed, had its name changed, or is temporarily unavailable.  Please review the following URL and make sure that it is spelled correctly.

Requested URL: /CustomError.aspx



Once this happens you can go backward page numbers but you can not go forwrad any more.

 This is the code to populate the dataset<asp:GridView ID="GridView1" runat="server"
DataSourceID="ObjectDataSource1"
AllowPaging="True"
PageSize="5"
AutoGenerateColumns="False">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:Image ID="Image1" runat="server"
Imageurl='<%# "~/photos/" & Eval("[MLS Number]") & "_0.jpg" %>'
AlternateText="Main Photo"
CssClass="photo-float-left photo-border" Height="125px" Width="125px" />
<asp:Label ID="Label1" runat="server" Text='<%# Eval("[MLS Number]") %>'></asp:Label>
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<asp:Label ID="Label2" runat="server" Text='<%# Eval("[Street Number]") %>'></asp:Label>
<asp:Label ID="Label3" runat="server" Text='<%# Eval("Direction") %>' Width="16px"></asp:Label>
<asp:Label ID="Label4" runat="server" Text='<%# Eval("Address") %>'></asp:Label>
&nbsp; &nbsp; &nbsp;
<asp:Label ID="Label5" runat="server" Text='<%# Eval("[List Price]", "{0:C}") %>'></asp:Label>
<li>BR:
<asp:Label ID="Label6" runat="server" Text='<%# Eval("Bedrooms") %>'></asp:Label>
/ Full Baths: &nbsp;<asp:Label ID="Label7" runat="server" Text='<%# Eval("[Full Baths]") %>'></asp:Label>
/ Half Bath: &nbsp;
<asp:Label ID="Label8" runat="server" Text='<%# Eval("[Half Baths]") %>'></asp:Label></li>
<asp:TextBox ID="TextBox1" runat="server" Height="80px" Text='<%# Bind("[Public Remarks]") %>'
Width="344px" Rows="3" TextMode="MultiLine" Font-Size="X-Small"></asp:TextBox>
<hr />
</ItemTemplate>
</asp:TemplateField>

</Columns>
</asp:GridView> 

Thanks,

Tony