urlrewritter not working in gridview with specified pagesize

urlrewritter is not working 

and my code shown below

student.aspx

 <asp:GridView ID="GridView1" runat="server" AllowPaging="True"
                    AutoGenerateColumns="False" DataKeyNames="aptitudeid"
                    DataSourceID="SqlDataSource1" PageSize="3">
                <Columns>
                    <asp:BoundField DataField="aptitudeid" HeaderText="aptitudeid"
                        InsertVisible="False" ReadOnly="True" SortExpression="aptitudeid" />
                    <asp:BoundField DataField="aptitudename" HeaderText="aptitudename"
                        SortExpression="aptitudename" />
                    <asp:BoundField DataField="aptitudetype" HeaderText="aptitudetype"
                        SortExpression="aptitudetype" />
                    <asp:BoundField DataField="aptitudevenue" HeaderText="aptitudevenue"
                        SortExpression="aptitudevenue" />
                </Columns>
            </asp:GridView>
        
        
        
        <ul>
            <li><a href="/student/Books.aspx">Books</a></li>
            <li><a href="/student/DVDs.aspx">DVDs</a></li>
            <li><a href="/student/CDs.aspx">CDs</a></li>
        </ul>
        when click  Books,DVDs,CDs its work fine but  not working in pager control inside gridview

my web.config page

<rewriter>
   
    <rewrite url="~/student/(.+).aspx" to="~/student.aspx?category=$1" />
  </rewriter>

Thanks advance...