track-results have multiple entries with searching in Database

[1000herz]

Hello,
X5, new Release (22.02.2007) - i build the database new. If i use any search-option in the database the searchfunction gets some result, but i get a lot of songs MULTIPLE. Do anyone know why this can be? the tracks are often without  full id3tags.
(i initialized the database new - with no sucess.) What goes wrong, what do i have to do?

thanks for yout help