I am using modal forms and it works great with most browser, but I just noticed that I systematically get a message in IE8: A script on this page is causing your web browser to run slowly, if it continues to run your computer might become unresponsive.

The script doesn't seem to take that long but enough for IE to complain.

This is systematic (the message will show for the login, register and forget password form).

Has anyone faced this problem?