With my UDOO Quad the VNC's working just fine (i followed the tutorial). What part of the tutorial didn't work out?
Just to confirm i was able to setup VNC on the 12.04 image using the tutorial steps without any issues also. So yes, please let us know exactly what issues you are having with the setup process
Thanks one and all for the diagnostics work. The .xsession and keyboard information solved my problems that I've been fighting.