help, lost the tops of windows in KDE 4.X

[Arthur Marsh <arthur.marsh@internode.on.net>]

Hi, I've lost the tops of windows and hence the ability to move them, 
and also the ability to switch tasks with alt-tab on my other machine 
and wonder where I should go looking to fix this.	

Installed includes:

ii  kde-plasma-desktop                            5:77+deb7u1 
                 amd64        KDE Plasma Desktop and minimal set of 
applications
ii  kdm                                           4:4.11.13-2 
                 amd64        KDE Display Manager for X11
ii  plasma-desktop                                4:4.11.13-2 
                 amd64        KDE Plasma workspace for desktop and 
laptop computers

Some process of upgrading attempting to remove apparently un-needed 
packages lead to this situation and I've been experimenting, using the 
aptitude logs as a guide to re-installing things.

Any suggestions on what to check for or do to restore this functionality 
are welcome.

I'm happy to supply more details as needed.

Arthur.