Thanks Ryan.

I did indeed have a previous version of NAV installed and the subscription claimed to be valid until around October/November 2012.  However, when I could not get LiveUpdate to work, and in view of the data recovery that had resulted from the bad block incident, I thought that it would be safer and simpler just to buy the latest NAV and start again.

Later today when I have some time, I shall try uninstalling and reinstalling.  If that fails, I'll send you the log.

Fingers crossed!

John.