jQuery times out on /admin/build/features

Every single time I access /admin/build/features I get the following JavaScript alert (after waiting a good 10 seconds for the page to finish initialising)

A script on this page may be busy, or it may have stopped responding. You can stop the script now, open the script in the debugger, or let the script continue.

Script: http://concern.kirkdesigns.co.uk/sites/all/modules/contrib/jquery_update...

After that, if I press continue, the page finally finishes initialising after another couple of seconds, and the Features UI functons fine (though it is very slow - but that's another issue).