All of that changed with Virtualbox 2.2.2.
Since GNU/Linux generally makes much better use of system resources than does Windows, it is much prefered to run a Windows guest in a GNU/Linux host than the opposite.
Of course, one rarely needs Windows at all, but I am back in school and Kaplan University is very Windows-centric. I am required to have a Windows OS as well as M$Office 2007 or later.
I thought to simply run WinXp in Virtualbox on my newly installed UbuntuStudio 9.04. It should be easy and take less than an hour to install and configure. This was not quite the case.
After installing Xp in the VBox I was appalled to find that I had no internet connection. Actually, the OS didn't even recognize the nic. Apparently the AMD PCnet Ethernet driver is no longer in the Virtualbox Guest Additions.
After much Googling and tweaking I am happy to present my solution using the PCnet Fast III for anyone else who may encounter this.
Basically: 1. Install the driver in the WinXp guest. (I used a Shared Folder to get the file from the Host to the Guest) 2. Install the driver. 3. Go to the Device Manager and Update Driver. The OS should now recognize and configure the network card. Enjoy!