Nevermind...I see the problem.
There are two "year" references for the metadata in the id3 struct: id3.year (an integer) and id3.year_string (pointer to a string). The database is only storing the integer value of id3.year; however, the vorbis date tag uses id3.year_string since it can contain non-numeric characters.
This is a bug, I'll add my comment to the FS page.