Keyboard layout trashed

[Colin Paul Adams]

Help!

I've just re-booted my system after an update, and my keyboard layout
is wrong.

I have a Logitech deluxe 250 keyboard. I tried going into
System->Preferences->Hardware->Keyboard - it showed me a USA layout
(nothing else, although I am in United Kingdom, and my system has long
be configured that way). So I tried to add a layout. I could not find
my keyboard in the choices under Logitech.

Worse, every layout I looked at (and not just logitech) did not show
the full number of keys (the key between the left-hand SHIFt and the Z
- labelled \ on my keyboard is missing).

How can I select the correct layout?