mysterious problem with playlist sony walkman x1050

[naminis]

Hello,
Im at war with my sony walkman x1050 for a few days now.
The problem is with playlists
I tried winamp,media monkey, walkmanMTP, WMP.
When I sync playlist(I select playlist, right mouse click, select add to sync list) and then sync to walkman with windows media player 12, But this action only transfers songs to music folder, playlist is not created.
I downloaded Sony MediaGo program. It transfers playlist to my walkman, I can see it in Computer> Walkman>PLAYLISTS> myplaylist.pla . But in my walkman, I select Playlists and it gives me an error : "no playlist available. please connect to compliant software or device and transfer playlists".
Why it gives me this error if there's a playlist (myplaylist.pla) in playlists folder ?
With walkmanMTP program, when i make playlist and press Sync, I imediately get error: error syncing playlist.
Winamp, mediamonkey creates .m3u playlists in my walkman, which I read is not supported by walkman.
 
Maybe someone can help me, because it's so annoying, seems that my sony walkman doest want to have playlist inside :/ .

 

[naminis]

a little bit more specifically:
 
1. Tried with Windows Media player. Created playlist, then selected add to sync list, and then
pressed Sync Now. But it only transfered songs to Walkmans Music folder, playlist wasnt created
in playlist folder, or in any other folder.
2. So I downloaded Media Go, synced playlist from my library to my walkman. Then I checked
Computer>Walkman>Playlist folder, and saw that myplaylist.pla appeared in walkmans playlist
folder, and playlists songs was transfered to  walkmans Music folder.
I disconected walkman, pressed search icon, selected playlist and it gave me error: "no playlist
available. please connect to compliant software or device and transfer playlists"
Why it gives me this error, if playlist  myplaylist.pla is in walkmans playlist folder?
I also tried to sync playlist with Winamp, MediaMonkey, WalkmanMTP, MusicBee, and it didnt work
also.
Maybe You can help me?