Thanks. Whatever happened it worked for me now so grateful for your intervention. When I did subsequently log in I thought I'd told it to take me to questionnaire.php but it took me to the login page again saying I WAS logged in. Presumably that's just a tweak somewhere to the 'if successful' redirect. If you know offhand where I need to tweak that it'd be handy but otherwise I'll take a trawl thru.
Thanks as ever Ray