Search problem in Omeka 2.4.1

Hope someone can help!

In migrating my Omeka site I have now found that my search form has stopped working. The homepage (where the search box is) just refreshes when a search is attempted. I've noticed that the search link generated doesn't include the '/items/browse' before the rest of the link like it used to. In other words:

Link generated now (not working):

Link generated before (working):

If I paste the correct link into the browser, everything works fine, so how can I edit the link generated by the form, what file would I need to edit within Omeka?