virt-viewer does not send ctrl-alt-F1, ctrl-alt-f2, ..., ctrl-alt-del

virt-viewer does not send any of
* ctrl-alt-F1
* ctrl-alt-F2
* ctrl-alt-F3
* ctrl-alt-F4
* ctrl-alt-F5
* ctrl-alt-F6
* ctrl-alt-F7
* ctrl-alt-F8
* ctrl-alt-F9
* ctrl-alt-F10
* ctrl-alt-F11
* ctrl-alt-F12
* ctrl-alt-del
* ctrl-alt-bcksp

selecting from menu "send key > ctrl-alt-*"

virt-viewer is version: 0.4.1-1ubuntu2
libvirt-bin is version: 0.9.2-4ubuntu15.2

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: virt-viewer 0.4.1-1ubuntu2
Uname: Linux 3.2.16 x86_64
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Thu May 3 04:23:31 2012
InstallationMedia: Xubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
ProcEnviron:
 PATH=(custom, user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: virt-viewer
UpgradeStatus: No upgrade log present (probably fresh install)