Iphone doesn't sync local files

[stefoulus]

I use macbook and iphone

when i create a playlist with local files from my harddrive on the mac, the playlist also shows up on my phone with the right number of songs in it, however when i open the playlist it's empty.

Local tracks that that get identified by spotify get synced though, but theres no sign of the "unofficial" ones.

i already rebooted both devices and also reinstalled the apps on both, making no difference...

any help??? thank's a lot!!!