Hi,
That almost always has to do with what you have in your master page. Sometimes the master page contains invalid HTML or the content place holder is just place at a place when the TabStrip is rendered, it would form invalid HTML. For example, say the master page is:
Code: HTML/ASPX
<table>
<tr><td>Hi!</td></tr>
<asp:ContentPlaceHolder runat="server" id="content">
</asp:ContentPlacerHolder>
</table>
And the content page is:
The final rendered page will be:
Code: HTML/ASPX
<table>
<tr><td>Hi!</td></tr>
<div>There!</div>
</table>
This is invalid. Most browser can tolerate such code, but some browser tolerate it better than others. When JavaScript is run on such objects, the result is mostly unpredictable.
As a way to narrow down and eventually locate the part that causes problem, you can try it without the MasterPage first; Then gradually comment out blocks in your MasterPage and see if the error occurs.
Please let us know if that solves the problem.
Thanks