Configuration:
I am running Ubuntu 8.10 (Intrepid Ibex) [32-bit] on a virtual machine running in VirtualBox on a Windows XP system.

Problem:
Neither Sound Juicer or Rubyripper see audio CDs when I insert them into my optical drive.

Helpful Info:
--- Nautilus mounts data discs just fine, so I know the virtual optical drive works.
--- Windows Media Player on the host system can play the CDs just fine, so I know the CDs aren't ruined.
--- VLC in Ubuntu also can't play the CDs, so it isn't just ripping software.
--- CDs tested: Astro Lounge (Smash Mouth) and Flight of the Conchords (Flight of the Conchords), one of these CDs in pretty old and the other is fairly recent... so I doubt this is some new DRM issue (unless there is some basic package I need to install in Ubuntu to play audio CDs altogether).