I am getting a flood of
SCRIPT5007: Unable to get value of the property 'jQuery17209514285345432955': object is null or undefined
jquery-ver-1348220874405.js, line 3405 character 3
errors to the console.
The problem can also be observed in the simple example
Just open a modal window and close it by the X in the corner. Observe how the console is flooded with error messages. IE9 in IE8 mode will also do.