Vanilla moved to new server now missing checkbox tick icons
I had a basic install of 3.1 using Boilerplate theme on a test server. All functioning OK. I've moved it to the live server with a different domain name, updated the config info for database - that seemed to go successfully and forum is working. However, I noticed that the tick icon on any checkboxes was missing. There's a 404 message in the browser console.
I've since upgraded the installation to 3.2 to see if this solves the problem - again this went smoothly, however the issue still persists. I've attached a screenshot with the console error.
Any help appreciated.