That seems to be a well known issue with VNC software on Linux. I've hit it myself a few times. Here's the next question. Are you running KDE or GNOME? Here's what you should try doing.
At the "~/.vnc/xstartup" path to TightVNC's startup file, at the last line in the startup file, there should be something such as "x-window-manager &" filled into the value. If there is, replace it with the following code.
For GNOME, type in "gnome-session &" without the quotation marks.
For KDE, type in "startkde &" without the quotes.
Try this and see if this works. Don't forget to shut down the TightVNC server before you do this, and restart it afterwards when you save the file. This is working off of a problem I had to fix one time with Kubuntu, so this might not work, yet again, it just might.
EDIT: The ~/ is referring to /home/youruserdirectory/
If this doesn't help, try visiting this site.
http://www.linuxtopia.org/HowToGuide...x_Windows.html