Your original post indicated you are using IE 6. WebUI Test Studio supports IE 7 and above.
Since your original post we have released a service pack. Please try upgrading to the latest version and retest to see if your crashing problem persists. If it does then it is also possible there's a conflict with a third party IE add-on. Please try disabling all IE add-ons under Tools -> Manage Add-ons and see if the problem persists.
the Telerik team