I suppose I could have the sync continue regardless, what was it in your library that was causing the problem? The "RebuildOnSync: Yes" goes in the notes of your playlist - if you click on your playlist in the MC tree, above the list of files there's an area with a "Play" button etc. Below the buttons, there may be some text "Click here to add notes", or the text may have info about your playlist - just click on that and you can edit the text.
Found that notes part. Thanks! Regarding the errors: I am not sure why exactly the tool stopped at the lines below. The songs were always playing fine in MC and Itunes and on my ipod. I paste some of the 'last lines' below for you (each comes from a different sync session that could not finish because of that element)
1)
<Track Filename="J:\Musik\Incubus\Make Yourself\Incubus - Nice To Know You.mp3">
<Lyrics ChangedIn="iTunes" OldValue="
2)
<Track Filename="J:\Musik\Madonna\Music\Madonna - 02 - Impressive Instant.mp3">
<AlbumArtist ChangedIn="iTunes" OldValue="Music" NewValue="" />
<Lyrics ChangedIn="iTunes" OldValue="
3)
<Track Filename="J:\Musik\Seal\Best 1991-2004 (2004)\Seal - Best 1991-2004 - 08 - Love's Divine.mp3">
<Year ChangedIn="iTunes" OldValue="0" NewValue="2004" />
<Lyrics ChangedIn="iTunes" OldValue="
Hope that helps somehow! I think it might indeed be a good idea to allow via a checkbox in the settings to 'ignore errors during sync'.