This bug applies to Microsoft Internet Explorer and its Vector Markup Language (VML) only.
In MSIE 7 (at least) an error is raised when this jQuery is executed:
The error first occurs on line 1407 (and then subsequently on line 1162) and is described simply as "Failed". It is raised when an animation is attempted and then subsequently whenever the page is unloaded (even after the page is reloaded) until the entire browser is closed and restarted.