Website Exhibiting Strange Behaviour After Upgrade

Hi there,

We have recently upgraded the site below to the latest version of Perch Runway and are seeing some issues.

http://keningtons.com/

Chrome looks fine, but in Firefox for instance there is a strange input box with the word 'lebowski' being seen at the top of the page.

Is this because of the upgrade or is this something else?

Thanks for your time and help.