I believe that the backup thing is only allowed where the copyright owner explicitly allows for you to have make a backup in their copyright declaration as part of the whole delegation of rights aspect of copyright law in the UK.
Where it isn't explicitly stated, you have to assume that backups aren't allowed.
Paul
I'm afraid not. The backup of computer programmes is a statutory right. The copyright holder has no say.
It's a bit like the literary study part where you can quote excerts from books. Some books will state this is permissable, others not. That does not take away from the fact it is a statutory right and you can do it legally.
I suspect the backup of computer programmes was allowed due to the volatile nature of early storage media. Tapes and early floppies could become easily damaged. A rare piece of pragmatic UK law.