I seem to have sorted it. Having recently been away, I have taken a lot of photo's and some video's. It appears to be over 3GB's worth. As my BB upload speed is 1Mb/S, the transfer appeared to be timing out. Although this wasn't obvious as no 'time out' messages were shown, just 'backup failed' etc.
To resolve the issue, I used the Windows iCloud Utility to delete the incomplete backup from the iCloud servers, and also toggles iCloud Backup off/on on the iPhone.
I then unchecked the individual apps from the iCloud backup procedure that contained the most data, I.E. Camera, iPhoto etc. Then I started a backup and all went well completing in a respectful amount of time without a hitch.
Next I simply, one at a time, enabled the Camera, iPhoto app, doing a backup after each instance. Again all is well, backup completed. I now have a FULL backup on the iCloud.
It really shouldn't have been so complicated. Not sure if it was simply the amount of data I was trying to upload or whether there is some other limitation.
I posted back in a effort to help others.