Thanks DaveRo - I've just done it, and the URL was what it should be. So I've learnt something, but it didn't fix it.

And thanks Andrez too. The trouble with being careful about updates is that though the ipad is magic, a ot of the magic is hiid, so you can't fiddle around with it so easily as you can with a Pc or Mac. I'm a lot more choosy when I'm on my PC.

I think going back to Apple to sort this might be necessary. There's no way to reinstall Safari - I've hunted roundabout that.