I have always used four different wallpapers for my four virtual desktops. Now, after update to 4.9, I can't do it: when I change wallpaper, it is used on all four desktops. It all started after first reboot after update, when one of the wallpapers came to all desktops. Is it a new «feature» or a bug?

P.S. I don't use activities.

Oh, sorry, I'm an alarmist.

The situation described above seems to be a single-time bug. After second reboot all desktops got their previous wallpapers back, and I can change the wallpapers separately again.

What could it be? No KDE-related packages were installed or updated between these two reboots.

It is possible this was caused by configuration migration, as the way this was setup changed between KDE 4.8 and 4.9 I believe. The involvement of Activities was altered I think.