I was having a devil of a time trying to get TweetDeck to even install under Ubuntu 11.04 until I came across this fantastic tutorial by deepok1968 on YouTube. The problem boils down to the Adobe Air installer not being all that happy with x64 systems in its native state.
If you visit the video page you can get a copy of the commands that he uses. I stuck them in a bash script so that I can re-use them if I need to do the install again.
Now I just need to figure out how he got that wicked looking OSX style dock…