(unexpected)
Conclusion (for anyone stuck with the same problem one day).....
In the absence of any further suggestions, or promised reply from Ahead (Nero) Support, uninstalled/reinstalled.
Same problem; hmmm.....
Uninstalled again and installed Roxio alternative.
Same problem; TURBOhmmm.....
Computer very shortly
locked up. ...Resorted to Task Manager and was surprised to find only application running:
DVD Region+CSS Free. ...Had installed this fairly recently, certainly since I last tried to copy a CD. ...Uninstalled this (plus Roxio), reinstalled Nero and now all is well (!).
NB: In fairness to
DVD Region+CSS Free they do not claim to support DVD-RAM drives, although suggest experimenting with the trial software, as it sometimes works. ...I did this and after extensive experiments with various multi region DVD's, it performed perfectly. ...The side effects have only come to the fore now, although almost worth it for the ASPI angle previously (something new to me).
All not lost,
DVD Region+CSS Free now configured in install/uninstall to suit.