Hello,
I ran into an issue on one of my Oracle applications servers this morning, and wanted to post what I found that helped me resolve the issue.
I was running vncserver, and when I tried bringing up the viewer, I got the black screen. I checked that my xstartup file under /home/user/.vnc was setup properly:
#!/bin/sh
# Uncomment the following two lines for normal desktop:
unset SESSION_MANAGER
exec /usr/bin/gnome-session
[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
startx &
twm &

But, what it turned out to be, was the users account did not have all of the gnome files, and directories in their home directory. So, when starting vncserver as that user, it didn't have all of the information it needed to start properly. I remove all of the desktop and .gnome files, and logged the user out, then logged them back in to re-create those files, and voila it worked! Hope this makes sense, and helps someone.

Hi am having the same issue can you tell me where the gnome files are that I need to remove and the process for adding them back again.