Just received my Alienware M15x and install Ubuntu 8.04 on it.
No problem except for the sound.
Need to add the line
options snd-hda-intel model=mbp3
Another little issue if you’re using AMsn and you don’t have sounds when you receive a message or when someone connect:
Go to Accound / Preferences / Others and replace
to use alsa sound server instead default library.