Don't replace imported

Let's say i have a playlist with 10 songs in MIXO. I export it in Traktor.. I go to traktor and i make some changes and divide the 10 songs in 2 playlists of 5 songs and delete the 1st playlist of the 10 songs... When i go back in MIXO and import again the collection from Traktor to Sync them, it adds the 2 playlists with the 5 songs but it does not delete the other one... That also happens if i rename, change location of folders etc... If i do a lot of changes when i am in Traktor and then i have to manualy delete in MIXO its really hard with a big collection... Do u get what i mean?? :D