It turns out to be a bit like a major model update on a car. They can do all the testing in the world but when it gets out in the real world you always find things that don't quite work in a different environment.
After discussions with the developer it has been decided to wait for a revised version which should come out at the end of the week. There are a number of hot fixes that need to be done for this version and it is better to get them done in an official release rather than fiddling under the bonnet.
I will probably wait until mid next week to see what other admins report.
