asp:Timer control is endless loop only in IE, FF is ok

Hello,
 
As the subject implies I am attempting to use a timer control on a content page for a master.  The master doesnt do anything with the timer, but does contain the scriptmanager.
The content page is basically this
 
<div runat="server" id="divLoader">
   <asp:Timer ID="Timer1" runat="server" Interval="200" ontick="Timer1_Tick" />
</div>
<asp:Panel ID="pnlRepeater" runat="server" Visible="false">
   < -- repeater is here -->
</asp:Panel>
And back end is basically this:
Here is page load
        if (!Page.IsPostBack)
        {
            Timer1.Enabled = true;
    &nbs ...