I tried your advice to erase the DVD Ram disk. The good news is that it worked and I have now backed up my data. For info only - the erase process was very slo-o-o-o-w (I almost gave up on it) and backing up also took a lot longer than backing up to a DVR/RW. The reason I wanted to use DVD Ram is that they can be re-written to for ever and a day - some reviews estimate 100,000 times, and I am constantly adding and deleting photo's and clipart.
Thank you very much for your help.