Enlarge image position problem at IE9

Enlarge image position problem at IE9

There is a bug with http://demo.opencart.com at IE9.

The enlarge image of the products does not stay the center of the monitor.
In fact, the bottom part of the enlarge image goes outside of the monitor.
And the enlarge image can not be moved.

Please someone solve the problem.

Thickbox was developed before IE9 come out.
May be you want to check this thread for another information.