TabPanel ignoring the tab I change to on postback

Hey folks, I know this has to be one we have all seen a time or two.  I'm trying to get my gridviews to not flicker when there is a partial post back so I'm using AjaxUpdatepanel with a timer as the asynch control.  What happens is the page no longer flickers.  However, when the page does its asynch postback, if I have another tab selected, teh tab index gets reset to 0.  Anyway, onto my code:

aspx:

<asp:UpdatePanel ID="updGlobal" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="true"><Triggers><asp:AsyncPostBackTrigger ControlID="Timer1" /></Triggers><ContentTemplate><cc1:TabContainer ID="TabContainer1" runat="server" OnActiveTabChanged="Tabs_ActiveTabChanged" Width="100%" ActiveTabIndex="0">

.cs

if (!IsPostBack)
    {
        try
        {
            TabContainer1.ActiveTabIndex = (int)ViewState["ActiveTab"];
        }
        catch
        {

        }
    }

    protected void Tabs_ActiveTabChanged(object sender, EventArgs e)
    {
        ViewState["ActiveTab"] = TabContainer1.ActiveTabIndex;
    }