A quick update on this as I know it has become a super-star bug. Not good news. I have reinstalled, error hunted, written on support forums, turned off all of ARRSE's modifications that might interfere, checked the database for errors and generally beat my head off anything within reach. Nada. At the moment I'm waiting on responses from some other webmasters who have previously posted about the same symptoms on support forums, and who now have working sites. I'm going to cut my losses and stop my own bug funding efforts until I hear from them, as the next step will be a time-consuming expedition in to the code that runs the Likes which I'm not familiar with. In summary, no news, but I am trying and it is certainly not forgotten.