Vista - ObjectDataSource returns from cache even if select param is differ

Following ObjectDataSource's method returns data from Cache without calling
DAL object method (XXX.Dao.GetClientingControlNumbers) even if parameter
(primaryControlNumbers) value of select method is different from previous
call.

Please help............

List<string> list = (List<string>)ObjectDataSource1.Select();


<asp:ObjectDataSource ID="ObjectDataSource1" runat="server"
SelectMethod="GetClientingControlNumbers"
TypeName="XXX.Dao" OnSelecting="ObjectDataSource1_Selecting"
EnableCaching="true" CacheDuration="1000"
CacheKeyDependency="MyCacheKeyDependency" CacheExpirationPolicy="Absolute">
<SelectParameters>
<asp:Parameter Name="primaryControlNumbers" Type="String" />
</SelectParameters>
</asp:ObjectDataSource>