Woop - woop - Breakthrough.......... I've revisited this again and now at least have a recipe on how to display the handles or not.
I should point out, that I normally work with the PRVs docked in the multidock.
If I undock the PRV and disable floating the "controller handles" view state option then works perfectly and instantly as it should. As soon as I enable floating the Controller Handles view state is locked to whatever it is set at when floating is enabled.
This probably explains why it is working for some and not me. If it works for you I'm guessing you haven't got a floating PRV.
This is consistent for me and at least I can now work round the bug, as well as report the bug properly. I'm guessing that the second PRVs I could see handles in, have at some point been non-floating when I set the option.
Thanks to all, that have helped out in this thread. It's appreciated.