I can confirm zzeliminators problem although it's not a vista thing.
With 3.316, using a standard named HD track, if you tell Hoster to ignore the track info, Hoster will give it the next available track number.
Exact same setup in 3.317, Hoster will give the error message he reported in his original post.
Oddly after clicking "no" to seeking help in the message, Hoster appeared to finish the import without a track number and logged it in the imported files log, however the song was nowhere to be found in the database
The KMA is in the Songs folder but it's header info is not in the database.
Something to look into.
Sam