Hi,I read an article which stated that the .htaccess file is a possible cause of the 500 errors on 1and1. I asked 1and1 for access to remove or modify this file to check but for some reason they stuggled with the concept. Anyway, I gave up and moved the entire application and database onto a different server and it all started working again.Obviously I've not really figured out what it was that caused an issue on the 1and1 servers.Thanks for the help anyway.