Blimey - thanks for all that - here are the results.

This is because the url in config.php and uu_default_config.pm are different.
yup - I'd used www. and without (numpty newbie mistake)

You need to set paypal email in admin area.
Had done that but had left "test payment" on.

Only reason for this is your mail server is not able to send mail or mail server is black listed. vshare use php mail function, so if that works, mails will work.
Interesting one this - the error is not showing at vshare - but on logging into the cPanel and then webmail I have found the following (one example of repeated error)

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

richard@******.*****
Gid 32035 is not permitted to relay mail, or has directly called /usr/sbin/exim instead of /usr/sbin/sendmail.

------ This is a copy of the message, including all the headers. ------

Return-path: <[email protected]>
Received: from thisphot by server48.hosthat.com with local (Exim 4.66)
(envelope-from <[email protected]>)
id 1ITmr5-0000A2-W6
for richard@*****.****; Fri, 07 Sep 2007 23:03:16 +0000
To: richard@*****.****
Subject: About email verification
From: [email protected]
Content-Type: text/html
Message-Id: <[email protected]>
Date: Fri, 07 Sep 2007 23:03:15 +0000
This is on hosthat.com as recommended on this site so I am surprised at this failure - suggestions on a fix gratefully received

You can ask in the template modification forum.
Will do

Re: Logo problem - your answer

You need to set permission 777 images folder and all files inside it.
I have changed this (wasn't 777) - but this does not appear to have fixed - same issue. File upload does not change the logo itself. It has occurred to me that perhaps I should simply ftp a different file (with same name) to the images to see if this works - but then I decided I should do it properly through the admin screen - so suggestions welcome!