I used the built-in Ubuntu Software Center to get RR, and that installed version 0.5.7. RR has been extremely slow on 10.04 LTS for me. I uninstalled via the Software Center and downloaded the latest version, 0.6.2, using the instructions from the RR wiki. RR is still slow, but I see a huge improvement in performance in going to the latest version. I recommend it. Secure ripping is worth the wait.