IstateManager Problem

[dionysus_sh]

I am Developing a custom grid.i am managing my viewstate manually through implementing the IStateManager.
The problem is that NON OF SaveViewState And LoadViewState Events EVER get fired and i can't figure out why?!
i have seen lots of articles on it,Please Do not direct me to a link.i haven't found any answers by myself.Thanks In advance.
I have tried the simplest form possible to see what's wrong but i have the same problem in this little code again ,here is the code:


namespace GridControl
{

public class MabnaGrid :GridView, IStateManager
{
public MabnaGrid()
{
}
bool IStateManager.IsTrackingViewState
{
get { return base.IsTrackingViewState; }
}
void IStateManager.TrackViewState()
{
base.TrackViewState();
}
object IStateManager.SaveViewState()
{
object[] State = new object[2];
State[0] = base.SaveViewState ();
State[1] = "hi";
return State;
}
void IStateManager.LoadViewState(object state)
{
base.LoadViewState(state);
if (state == null)
return;

}