If you don't add an album name to a song, iTunes just can't handle it. It seems to be central to everything.
For instance, the album artwork. Today I've been trying to add album art to individual songs off an album (the album is incomplete, so I've left the album field empty - just trying to add the cover art) and it simply won't do it. Tried every combination - clear album artwork, get info + checking the box to clear, going to the artwork tab and clicking Remove, repeating process, etc... nothing will fix it. If there are several different songs, all off different albums, but by the one artist cover flow just seems to take the first cover art and display it for all songs, thinking that is the cover for "Unknown Album" (this is very hard to explain without seeing it, sorry
)
In iTunes 7 I was able to do it... I'm sure this new grid view (which you guessed it, is based on albums) in iTunes 8 has changed something that makes the program even more "album based".
Another example, turn your iPhone on its side and you see cover flow. But not cover flow for all songs with album art, only for songs that have a non-empty album field.
This has annoyed me in the past, but never has it actually caused a problem as bad as the wrong album art appearing in the cover flow
/end rant
