either that or remove the ~/.config/xfce4 dir all together.
Xfce will generate a new one the next time you log in
That dood it.
I first renamed it then rebooted.
I'm thinking it got corrupted somehow or other; I don't understand those things much.
Now my changes do work and all is well. I went back to the default window manager (the developers really uncorked a nice looking, fast wm, as they have so many other Vector releases over time).
Thanks very much for responding, I appreciate that. Try to keep in mind that I'm very, very old, and thus.. senile. Therefor I'm liable to post about any little problem here.