I have had several teachers report script timeouts when checking/unchecking boxes while importing items from other courses. The common thread is the courses the teachers are importing from have a large number if resources/activities (150+). I can reliably duplicate the problem. Please see image below of the script message in FF. I also have the issue with IE9. Even if the error message does not appear, it still takes up to 30 seconds for the check/uncheck action to complete. I would appreciate help getting this sorted out.
Thanks,
Rob