SYLUSNOZAKI Trance strange your having so much trouble - all the conversions we have done to h264 went fine, and we did a lot...what kind of input files are you feeding it.....
as for the avi and other formats its clearly stated they are not complete.
Also with the prefs, in your opinion the tab are in the wrong order - there no right or wrong order, check the human interface guidelines on apples website.
(Version 1.2.3)