System: Knoppix 5 DVD

Knoppix is normal running in init 5
If I try to start a second X on console 2 with startx -- :1, the graphic screen appears, the mouse-pointer is active for 2 seconds, after that I returned zu text-console with the following messages:

Code:
xauth:  creating new authority file //.serverauth.3854
xauth:  creating new authority file //.Xauthority
xauth:  creating new authority file //.Xauthority

X: warning; process set to priority -11 instead of requested priority -10

X Window System Version 7.0.0
Release Date: 21 December 2005
X Protocol Version 11, Revision 0, Release 7.0
Build Operating System:Linux 2.6.12-1-686 i686
Current Operating System: Linux Knoppix 2.6.17 #4 SMP PREEMPT Wed May 10 13:53:45 CEST 2006 i686
Build Date: 16 March 2006
	Before reporting problems, check http://wiki.x.org
	to make sure that you have the latest version.
Module Loader present
Markers: (--) probed, (**) from config file, (==) default setting,
	(++) from command line, (!!) notice, (II) informational,
	(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.1.log", Time: Thu Jun 29 14:50:46 2006
(==) Using config file: "/etc/X11/xorg.conf"
The XKEYBOARD keymap compiler (xkbcomp) reports:
> Warning:          Type "ONE_LEVEL" has 1 levels, but <RALT> has 2 symbols
>                   Ignoring extra symbols
Errors from xkbcomp are not fatal to the X server
Could not init font path element /usr/share/fonts/X11/TTF/, removing from list!
Could not init font path element /usr/share/fonts/X11/OTF, removing from list!
Could not init font path element /usr/share/fonts/X11/CID/, removing from list!
AUDIT: Thu Jun 29 14:50:51 2006: 3872 X: client 2 rejected from local host
  Auth name: MIT-MAGIC-COOKIE-1 ID: -1
AUDIT: Thu Jun 29 14:50:53 2006: 3872 X: client 2 rejected from local host
  Auth name: MIT-MAGIC-COOKIE-1 ID: -1
AUDIT: Thu Jun 29 14:50:54 2006: 3872 X: client 2 rejected from local host
  Auth name: MIT-MAGIC-COOKIE-1 ID: -1
AUDIT: Thu Jun 29 14:50:54 2006: 3872 X: client 2 rejected from local host
  Auth name: MIT-MAGIC-COOKIE-1 ID: -1
AUDIT: Thu Jun 29 14:50:54 2006: 3872 X: client 2 rejected from local host
  Auth name: MIT-MAGIC-COOKIE-1 ID: -1
AUDIT: Thu Jun 29 14:50:54 2006: 3872 X: client 2 rejected from local host
  Auth name: MIT-MAGIC-COOKIE-1 ID: -1

waiting for X server to shut down FreeFontPath: FPE "/usr/share/fonts/X11/misc:unscaled" refcount is 2, should be 1; fixing.
If I try to start Xnest :1, I get

Code:
  Fatal Server Error:
  Unable to open display "".
What is the problem?

Ciao
Frank