I ran into this problem, and Dr.Arthur had the same problem. He and Splitpaw from ubunite.com and I discussed this on Facebook. If you’re installing Ubuntu 10.04 and you have multiple displays, disconnect all except the main monitor. Otherwise, the Live CD will freeze on the splash screen. That’s just a purely empirical view based on two people’s experiences. Have you installed Lucid whilst multiple displays are connected? Leave a comment.