KDE 4.2
I’m pleased to say that by the magic of yum, KDE has been automatically upgraded to version 4.2 on both my home box and my work laptop.
At work, I can now use 2 screens again, thank goodness 
The 2 screen set up is slightly different now to how it was with KDE 3. Previously I had 2 separate X screens defined, one on each physical screen. The downside of this is that you can’t move windows between screens (the mouse pointer is the only thing that can do that). If you have Thunderbird email in one screen and the Firefox browser in the other, when you click on a link in an email message you get a message saying you can’t open another instance of Firefox because there’s already one running. So, the work-around is to just copy and paste the URL between the applications.
Anyway, with my new configuration I used the nVidia configuration utility (nvidia-settings) to configure Twinview. Now I can happily move windows between screens with no problems. Pop-up dialog boxes tend to appear on a random screen, but it’s not a big problem
So, overall, KDE 4.2 is what KDE 4.0 should have been to begin with.
Finally, KDE is back! Congratulations to everyone involved