Displaying items as "unknown" Bizarre software behavior. 1. I put two folders called "Great minds" and something else in Audiobooks subdirectory. In the menu I see one item under Audiobooks - "Unknown". It contains items only from the first subfolder I created. 2. Moved both subfolders in Music folder. Now I see one new entry called "Unknown" under Music, and now it contains files from both of my subfolders.
Does this mean that the folder must be a real artist's name? :-)
3. Copied one of the subfolders into Podcasts directory. Podcasts directory in the menu still says "[Empty]"
4. None of the actions 1-3 aree reflected under "Recently updated" menu item.
The Sansa Clip+ does NOT AT ALL use folder names for identifying songs/artists; it only uses the ID3v1 and/or ID3v2 tags stored inside of the MP3 files. If the "title" field of the ID3 tags is blank, it will use the full filename as the name of the song, and if the "artist" field is blank, it will be interpreted as "Unknown".
If your song titles/artists are showing up as "Unknown," it could be that the ID3 tags are not set in your files. To set up the ID3 tags, I would recommend using WinAmp ( http://www.winamp.com/ ) and Mp3tag ( http://www.mp3tag.de/ ).
ID3v1 stores less information and is limited to shorter text fields, while ID3v2 stores a lot more information and has virtually no limit on text length. To reduce filesize, I prefer to use ID3v1 most of the time, and use ID3v2 only when a title is too long to fit in ID3v1. (Some people set both the ID3v1 AND ID3v2 for compatibility with older devices, but I feel like this is a waste of space as most devices now recognized both tags, and in most instances you can fit all relevant information in either tag.)
Note that for MP3 audiobooks to work properly on the Sansa Clip+, the genre MUST be "Audiobook", and the files should be placed on the player in the "Music" folder. (It's okay to put files into subfolders inside of the "Music" folder.) The audiobook files will now show up on the player under "Audiobooks", and they will also be excluded form the randomized music playlist, so you can easily switch between listening to audiobooks and listening to music. To group the audiobook files properly, the "artist" and "album" should be set the same on each file.
Also note that when ripping audiobooks that span multiple disks, some people/programs tend to preserve the per-disk track numbers, so the tracks from disk 1 might be 1-27, the tracks from disk 2 might be 1-25, the tracks from disk 3 might be 1-26, and so on. Then when you go to listen to the audiobook, all the Track 1's will be played, then all the Track 2's, then all the Track 3's, and so on. Mp3tag is great for fixing this by renumbering all the tracks from 1 to infinity.
(Resist the temptation to zero-pad track numbers to make them line up nicely, with the likes of "01", "02", "03", etc. because some devices/software interpret this as base-8, so "08" and "09", which are not valid base-8 values might be interpreted as "truncate to seven" or "overflow to eight", and therefore screw up your playlist ordering.)
Ages ago I gave up on the extremely time-consuming effort of setting a unique title on each audiobook track, so now I name the files 1.mp3, 2.mp3, 3.mp3, etc. and just leave the title blank. When I go to listen to the audiobook, I look under Audiobooks -> [Artist Name] -> [Album Title] -> 1.mp3, and I find that to be enough information.
To simplify things even further, when I rip audiobooks, I use GoldWave ( http://www.goldwave.com ) to rip the enitre disk as a single file (or sometimes I'll take several short tracks and merge them into a single file, which GoldWave also does). This way, I'm only managing 8-12 files instead of 700-1000.