If you have a Kraken account (or create one), you can submit a ticket for this issue (a screenshot helps). There does seem to be some kind of issue with the MtGox claims site where certain users are finding that buttons aren't clickable. We are working with the trustee on the behalf of our clients to get this resolved.
Thanks for the advice and letting me know. I have made an account and sent a message to customer support. They sent me an email back and informed me that they have had a large number of tickets regarding gox so I guess I just need to wait and see.