While my MacBook runs OS X Snow Leopard, I do like to play with Linux on it via VirtualBox. Being the tinkerer that I am, I upgraded my MacBook's Ubuntu to the beta release of 10.10. There were two major glitches that needed addressing.
First, since this is beta, Sun/Oracle's Guest Additions won't work as they usually do. To get that nice seamless behavior, use the following at a command line:
sudo apt-get update sudo apt-get install build-essential linux-headers-$(uname -r) sudo apt-get install virtualbox-ose-guest-x11
Second, as often seems to happen for me under VirtualBox, the audio pitch was wrong. Fix this by creating the following file in /etc/modprobe.d/sound:
options snd-intel8x0 ac97_clock=48000 options snd slots=snd-intel8x0 # CvwD.FAMlirE10w6:82801AA AC'97 Audio Controller alias snd-card-0 snd-intel8x0
That one is a common issue, but I'm just scribbling it down in case I have to find it again with another update.
Footnotes: obviously create that sound file as root/admin and restart for the fixes to take effect.