2009.1 KDE4 ctrl-alt-bs, etc?

Does anyone know why ctrl-alt-bs and ctrl-alt-Fx key combos
do not work under KDE4 in MDV2009.1?  I found that the latest
X has disabled ctrl-alt-bs, so I re-enabled it.  Now it and the
combos to switch virtual terminals work at the login window,
but they do not work inside of KDE4.  Not being able to change
to a "console" isn't acceptable for some of my work.
Thanks for any help.
Norm