i just tested this, and ran into the the issue, which may actually be bug #561668 since the error messages seem to implicate .Xauthority management. with an X session already running on :0, i did:
$ xstart -- :1 xauth: error in locking authority file /home/zero79/.Xauthority xauth: error in locking authority file /home/zero79/.Xauthority xauth: error in locking authority file /home/zero79/.Xauthority xauth: error in locking authority file /home/zero79/.Xauthority X.Org X Server 1.7.6 Release Date: 2010-03-17 X Protocol Version 11, Revision 0 Build Operating System: Linux 2.6.26-2-amd64 x86_64 Debian Current Operating System: Linux a 2.6.32-4-amd64 #1 SMP Wed Mar 17 03:23:53 UTC 2010 x86_64 Kernel command line: BOOT_IMAGE=/vmlinuz-2.6.32-4-amd64 root=/dev/mapper/sda3_crypt ro Build Date: 23 March 2010 04:00:24PM xorg-server 2:1.7.6-1 (Cyril Brulebois <[email protected]>) Current version of pixman: 0.16.4 Before reporting problems, check http://wiki.x.org to make sure that you have the latest version. 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: Sat Apr 3 15:21:18 2010 (==) Using config file: "/etc/X11/xorg.conf" (WW) fglrx: No matching Device section for instance (BusID PCI:0...@1:0:1) found SELinux: Disabled on system, not enabling in X server No protocol specified waiting for X server to begin accepting connections . No protocol specified .. No protocol specified .. [...] giving up. xinit: Resource temporarily unavailable (errno 11): unable to connect to X server waiting for X server to shut down xinit: Server error. xauth: error in locking authority file /home/zero79/.Xauthority -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]

