Cash. Rate dropped so tried to modify in usual manner. Everything looked normal until I received the email confirmation which, despite showing reservation as modified, still reflected original rate, type and total. A quick check of Trips list confirmed nothing had changed. Repeated process and this time noticed that everything changed, but the final total (post-tax) stayed the same. Same result; necessary to cancel and re-book. Property is a domestic Fairfield and is my only remaining reservation in the new format.