Did you noticed this message when starting vnc?
/home/user # qchroot /home/user/MyDocs/bt5/bt5.img /mnt/bt5/
..stripping trailing slash...
Mounting...
using image file: /home/user/MyDocs/bt5/bt5.img
fs type is img
Don't know img: Using ext2 file system
Using ext2 file system
mounting /home/user/MyDocs/bt5/bt5.img on loop
.../home/user/MyDocs/bt5/bt5.img mounted on loop0
.
..
...
....
mount: mounting /var/run/pulse on /mnt/bt5/var/run/pulse failed: No such file or directory
Everything set up, running chroot...
[root@chroot: /]export USER=root
[root@chroot: /]vncserver -geometry 800x470
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LC_PAPER = "en_US",
LC_ADDRESS = "en_US",
LC_MONETARY = "en_US",
LC_NUMERIC = "en_US",
LC_TELEPHONE = "en_US",
LC_MESSAGES = "en_US",
LC_IDENTIFICATION = "en_US",
LC_MEASUREMENT = "en_US",
LC_TIME = "en_US",
LC_NAME = "en_US",
LANG = "en_US"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
xauth: (argv):1: bad display name "Mr_Pingu:1" in "add" command

New 'X' desktop is Mr_Pingu:1

Starting applications specified in /home/user/.vnc/xstartup
Log file is /home/user/.vnc/Mr_Pingu:1.log