Version: (using Devel)
Installed from: Compiled sources
In systemsettings -> keyboard & mouse -> global keyboard shortcuts -> kwin, I assigned CTRL+SHIFT+TAB as the shortcut key to "switch one desktop to the right". This doesn't work, even though it is listed as the assigned shortcut key combination. If I assign it a different combination, it works (I often use CTRL+ALT+RIGHT / LEFT, for instance).
Since I couldn't select 4.3.1 as the platform, it says "Compiled sources", but it is the kubuntu packages from their ppa backports repository.
Remark: Although it mentions alt+tab it's a duplicate as it uses internally the same functionality.
*** This bug has been marked as a duplicate of bug 174142 ***