Thanks. I have 2 Zen Cart installs - one is 1.3.5 and the other is 1.3.6. I will upgrade the 1.3 5.

I'm not sure if this relates to the problem though. On both installs I've noticed that in Shipping Modules the little coloured blobs remain orange unless I select --none-- for Shipping Zone, in which case they go green. So it doesn't like something in the way I've set up the Shipping Zones. I can't imagine what though (butts adjacent wall to aid thinking process).

Patrick