Thanks you fellows I just checked to do what pparks1 suggested - found no backup.
So have just run it again and 9Mmins for 49Gb so the first backup must have gone walkabout - everything seems ok now.
Oh and yeh the drive is in the blue port - thats what made wonder what the dickens was going on the first time.
Help much appreciated and so quick!!
The drive is a WD 329Gb part number WDBACY5000ARD-00 and has the 3.0 label attached to the lead.