The new version of cinelerra was just released:
http://heroinewarrior.com/cinelerra.php3
I compiled it from source, it works much better than the old release. Needs lots of horsepower to run properly.
If your looking for something just to edit out commercials use avidemux2 instead, but for post production work cinelerra seems to be more than capable once you learn how to use it.Give it a try.