iTunes 7.0.1.8 with svn 1376 worked quite fine (Debian on Kurobox). I just installed svn 1393 as well; the unknown meta codes are:
2006-10-14 14:54:35 (00070004): Unknown meta code: daap.songalbumartist
2006-10-14 14:54:36 (00070004): Unknown meta code: daap.songcategory
2006-10-14 14:54:36 (00070004): Unknown meta code: daap.songcontentdescription
2006-10-14 14:54:36 (00070004): Unknown meta code: daap.songlongcontentdescription
2006-10-14 14:54:36 (00070004): Unknown meta code: daap.songkeywords
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.is-podcast
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.mediakind
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.series-name
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.network-name
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.episode-num-str
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.episode-sort
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.season-num
2006-10-14 14:54:36 (00070004): Unknown meta code: daap.songgapless
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.gapless-enc-del
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.gapless-heur
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.gapless-enc-dr
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.gapless-dur
2006-10-14 14:54:36 (00070004): Unknown meta code: com.apple.itunes.gapless-resy
2006-10-14 14:54:58 (00070004): Unknown meta code: com.apple.itunes.is-podcast-playlist
2006-10-14 14:54:58 (00070004): Unknown meta code: com.apple.itunes.special-playlist
The loading is quite slow (due to the slow processor of the Kurobox probably), but succeeded, and files are playing correctly, so I wouldn’t assign the fault to the above unknown metacodes.
Bug: For some reason, all smart playlists show the full contents of the library. Those playlists all worked for some time with svn 1376, didn’t change them (until now to find why they won’t work currently).
Small bug: when removing a playlist that was opened for editing, the edit details will still show after the playlist was removed from the list above.