I hope to bring you some news. I worked out that the reason opengl does not work is because the nvidia drivers are installed with linuxmce.
I read that having the nvidia drivers installed can prevent X from working for some graphics chipsets, mine being one of them.
So I knew that my intel graphics chipset worked fine for virtualbox guest running Ubuntu 9.10 with Xserver 1.6. So short of having to to much effort I have taken a bit of a quick win approach by replacing the the symlink libglx.so pointing to the nvidia libglx.so.195.36.15
I then tested glxinfo and this indicated glx was working, so then ran AVwizard again with UI2, and it all worked perfectly fine.
replace /usr/lib/xorg/modules/extensions/libglx.so with the one from xserver 1.6 which I You can download here http://mce.commsbyte.com/index.php?option=com_joomdoc&task=doc_details&gid=30&Itemid=25
Now I wont lie to you, your opengl results in virtual guest will vary, mine seems to run nicely once i disable the screen saver, but at least I have a usable UI2 menu, granted its not native speed, but its good enough for what I wanted to do.
Please test and set to Solved if it works for you.