I stumbled across this and took me forever to figure out. There is another cubecap location in relation to the kubuntu-desktop install configuration, so when I installed kde-full, I still had kubuntu-desktop configurations, and they were preventing me from replacing in their normal location root/usr/share/kde4/share/kwin.
CapPath= script would disable this, but not replace.
There is another location, and it is
root/usr/share/kubuntu-default-settings/kde4-profile/default/share/apps/kwin