Hi 3Dillusions (?)
I have done a bug report.  Have posted one before and they were very helpful - in fact it is the same bug.  By changing the 'preferences' as they suggested the problem appeared to go away, but as I have now discovered it was the act of applying and accepting the 'preferences' - changed or unchanged - that got over the problem.  
The reason I merely entered it onto the forum was because I thought they would not be interested as a new version of the system had been released - but by putting on their it would inform any users of the system who were experiencing the same problems and perhapps bring it to the attention of technical support if they were interested.  Having checked through the forums today it was evident that a bug report would have to be raised.

That was complicated.  Possibly not logical.  Perhaps I should have said 'yes, done that'.

Regards
Peter