Thank you for getting stuck into this issue as you have Rod. It slipped down my inbox but came back to me just now when another user fravec replied.

I checked the paypal_functions.php file and mine, like flavec's, had false at line 647 and so I've changed it to 0 to see what happens.

It's possible, as you point out, that you had already fixed the setting on your site and that the zero you have in there is the corrected file.

I'll put a note in my calendar to check again in a few days and report back here what happens.

Thanks heaps, and thanks flavec too for putting your post in.
Regards
ROb