Normally, X allows you to access virtual consoles (via Ctrl-Alt-Fn, where Fn is a function key from F1..F6) and alternative resolutions (via Ctrl-Alt-Keypad +/-, if alternative resolutions are defined as accessible from /etc/X11/XF86Config. However, for some reason this feature was disabled after I updated from SuSE 8.0 to 8.2.
Strangely, I could still access virtual consoles and change screen resolutions from the kdm login window, or if I logged in as root. The problem only occurs after I was logged in as a normal user. It is possible to change the screen resolution using a program which can be started from `SuSE Menu'->System->Configuration->`Screen Size & Rotate'. This program appears as an `applet-style' icon on the KDE taskbar (/opt/kde3/bin/krandrtray).
To enable access of virtual consoles (and Ctrl-Alt-Keypad +/-) I needed to turn on 'Enable Keyboard Layouts' in the KDE Control Centre. This option is found under `Regional & Accessibility'->`Keyboard Layout'. My particular keyboard is a Generic 104-key PC (actually, it is a Logitech Deluxe 104, but the Generic option seems to work so far) with a U.S. English layout.
Some writers on the web suggest that /etc/X11/XF86Config also needs to be modified. In particular, under the ServerFlags section, I added...
Option DontZap off