Finally solved my backup problem. There was indeed nothing wrong with the keyboard just that the keyboard manual was a bit confusing.
Firstly when the keyboard is in backup mode it doesn't store the last settings that were used on the keyboard before you turn the keyboard off and then on again.
For the backup function to work, get the settings you want to store in backup on the keyboard, press the backup facility off then on. Then it will store the settings but only then. The keyboard will then start up with the settings in the backup memory. The manual is quite misleading.