>> That's a good idea, so I did it. After I sent "Ctrl-Alt-Del" from the
>> "F8-menu" of xvnc4viewer (when the screen was *not* locked), TDE opened
>> the "End session for 'ilya'" dialog (with a dragon sleeping on the
>> moon). And that is not the same dialog as I got by pressing C-A-Del
>> physically today.
>
> Looks like ctrl+alt+delete of vnc is not ctrl+alt+delete from the keyboard
> :-)
>
> You can try to figure out what is sent by calling "xev" and analyse the
> output.
>
>> Should I file a bug about it, or is there any other explanation for this
>> behaviour?

TDE monitors the first keyboard it finds for the Ctrl-Alt-Del keypress via
evdev.  The only ways to make this work are:
1.) if vnc registers as a keyboard to evdev somehow (unlikely)
2.) A security hole is opened by monitoring vnc for input
3.) (best) vnc is detected and the ctrl+alt+del input requirement is
deactivated

A TDE bug report on this would be a good idea.

Tim