Spurious text in compare popup

Hi there
Sorry I can’t give you a link to the page with the actual problem because it is dependent upon choosing products to compare before the problem arises.
Once products are chosen the resultant pop up gives the option to compare. Yesterday the popup was enlarging to show the products and the chosen attributes, today however clicking the compare button merely goes to an empty “Compare” page.
If it helps to identify the problem, yesterday there was spurious text within some of the attributes.
I haven’t installed or activated any other plugins nor have I added any products, as far as I’m aware the only process that has happened since yesterday is an automatic backup of the website overnight.
Thank you for your help in advance and keep up the good work.

The page I need help with: [log in to see the link]