This seems to have part resolved itself on the 3rd attempt.
There are two areas to fill in the email you would like the back up sent to. one under ‘general’ tab and the other under ’email to’ That appeared to help the backup go all the way.
Then, looking back at the backup log it says:
[28-Feb-2013 17:09:17] ERROR: Backup archive too big to be sent by email!
its not a big site. It woud be helpful to see how big the file is. It’s set to send max file size of 20mb…
Many thanks for the plugin and help.