Further to my report a little earlier on, I wish to confirm that the repeated problems I had were installing Jessie (stable) in ‘expert mode’; however I now find in default ‘install’ the 'Installation of Extra Software' proceeds after only a brief pause, to match software to the system. I checked by repeating the installation, and it worked again. I’m sorry I cant provide any more details, as I am new to Debian installation.
SIncerely, John Plumridge