Share to iTunes creates 3 identical files.

Question

Using iMovie08 ,let's start with a project called xxx.rcproject. This project is not shared to MediaBrowser.
When you share it to iTunes 3 files are created in the following locations.
(As an example I share the xxx project to iTunes using the medium size and this is what I get).
1.- First file inside iMovie project with the name equal to the size you choose to export (medium.m4v)
2.- Second file in Movies/iMovieSharing/iTunes with the same name as the project file plus the size (xxx - medium.m4v))
3.- Third file in Music/iTunes/iTunesMusic/Movies with the same name as the previous (xxx - medium.m4v)
All of them (except for the name in the first file) are exactly the same size, format, etc..
After some testing I discover that when you share to iTunes, iMovie automatically shares to the MediaBrowser, so here's the explanation of the first file.
If you select in iMovie "remove from iTunes" then the second file is deleted, and the movie does not appear in iTunes, but the third file stored in the iTunes library is not deleted.
If you on the other side delete the movie from iTunes, then only the third file is physicaly deleted and the second remain in the system.
It seems that the file that iTunes uses is the third one located in its library. This is the file you get when you choose "show in finder" from within iTunes.
You can manually delete the second file, and iTunes keeps showing and playing the movie from his own library.
Why is this duplication of the files happening? We are talking about video files, so big amount of disk space is involved.

Answer 1

Since iTunes does not have the option to move to its library (the option is copy not move) is there from iMovie a way to avoid duplicating the file in the folder iMoviesharing, or do I have to delete it manualy?
Not from within iMovie '08 itself. As previously indicated, deselecting the iTunes Advanced Preference "Copy files to iTunes Music folder when adding to library" is the only automatic way to prevent a file duplication between the shared folder and the iTunes library.
The same question goes for avoiding sharing to Media Browser.
None that I know of. In fact I have not gone through and checked this but I assume all of the "Share/Export" options that use the shared "H/264/AAC matrix selection window" will likely post a copy to the the named_Project "Movies" folder. Of course, you can simply modify the project following a "Share" action and it automatically deletes this file.
I know that there is some true in what you say but if I have to choose between having the movie prepared for exporting to another app, or saving disk space ( and we are talking about Mb eaters) I go for the second (I do not really need so often to use the movies that way, and, is it not possible anyway to just drop the file from itunes to GarageBand for example without using the media browser?)
Certainly. Actually, I do a lot of "drop-importing" and so use a somewhat different work flow:
1) I Use/re-use the same Projects and Events over and over. When finished with a project, I delete its content from the "Project" window but leave the named_Project in my list. I then close iMovie '08 and delete all contents from the associated "Events" folder used for that project at the finder level. Then, the next time I start a new project, I simply "drop-import" to the empty named_Event from within iMovie '08 and re-use on of the named_Projects which are pre-set for various specific uses. (E.g., 3:2 slideshow, HD widescreen, tutorial generation, etc.)
2) Unless "sharing" to my Gallery, I normally export projects using the "Export using QuickTime" option. This avoids the generation of a Media Browser file and allows me to add voice overs, enhance the audio, or add chapter markers in GarageBand before compressing my content for one or more specific target uses. I do normally leave the intermediate file used as the source for GarageBand available and simply delete the old one when re-using the GarageBand project file for my latest iMovie '08 project export. (I.e., I "replace" the old movie audio and video tracks with the new ones and delete the old intermediate file as soon as I close the GarageBand session having saved the new content under the old GarageBand project name.
3) Since the GarageBand projects are exported/compressed from the application directly to the hard drive, I have none of the file duplications to which you object up to this point. Normally at this time I archive a copy of my GarageBand output to an optical medium if it is important and then drop-import the file to iTunes, iWeb, iDisk, Family.com, etc. and delete the hard drive copy because the file is now located elsewhere if needed again. This work flow is probably not for everyone. It is not very "automatic" in terms of applications deleting the files, but it is methodical and seems to work for me.