I tried to install Ubuntu 8.04 in my brother’s computer, but the installer crashes everytime. So when I looked carefully the logs I realized the problem was the migration-assitant. Since the last version(I think!), to reduce the instalation steps, ubiquity doesn’t have anymore a gui option to disable the migration-assistant.
If you have problems with migration-assistant like me and you don’t wish download the alternate version, just run the follow command on a Live CD terminal:
sudo ubiquity –no-migration-assistant
Don’t forget send the bug report about it.