I have written up a bit of doco on this here http://userbase.kde.org/Kdenlive/Manual/Project_Menu/Stabilize

That page has some clips showing a comparison between the transcode and vstab methods.

Right now for me the transcode method crashes kdenlive with some file formats. For me it crashes with .mov, works with .dv

What version of kdenlive and melt are you using?

You could add comments to this bug report http://www.kdenlive.org/mantis/view.php?id=2900

I am using for all the latest versions, except for ffmpeg I am not sure.

"all the latest versions" from where ? Because, for example, "the latest version" from Ubuntu software center is not the latest version.

And when you do not "get any real results" do you mean the stabilize is crashing or just that you are not happy with the result?

All latest from sunab ppa. No the clips crash and if not the result has no effect. The software crashes with my system continuesly so I suppose something must be wrong in general, as I cannot image that this software does not work at all.

thx
Eric