VirtualBox Tips

I've been experimenting a bit with Sun's VirtualBox over the last few days. For the most part, its been pretty smooth. I now use this instead of VMware. I thought I'd pass along a few snags I ran into to save someone else some trouble. When upgrading, uninstall the previous version first (they claim it can be installed over the old version, but its given me problems both times I've tried to upgrade that way). It won't delete your VMs. Also, for those running Vista/Win7, when installing, run the installer in administrator mode otherwise it seems to fail when trying to install the virtual network devices. I'm not sure why they don't have their installer set to require these permissions, and it doesn't seem to write a log either when it fails, making debugging difficult.