One of our web page crashes IE7. It works perfectly with IE8, however also crashes IE8 when in IE 7 compatible mode.

We do use Ajax tool kit (now part of ASP.Net Ajax Library). One difference between this page and other pages is that it uses update panel.

Let me know if anybody experienced similar issues and can share some insight.

Forgot to mention a potentially important detail: there are two update panels on that page.

The issue was finally resolved, and it was caused by a piece of our own javascript. Once that piece of code is removed, IE 7 no longer crashes.