whats wrong with "plasma-desktop-appletsrc"?
the bkp-file is how it should be
some crap is adding "[Containments]" repeatly
until today it was enough to copy "activityId" to
"[Containments]", remove the rest and hard restart
X so KDE has no chance to write his crap back
well, now after doing that 3 times i still sit in
front of a empty desktop witout any widgets