Problems with encoding of playlists

[etan]

Hello,

I have always problems trying synching Media Monkey with my Sony WalkmanNWZ-E585.
It takes a loooot of hours synching a selected number of playlists (just 4xxx tracks), converting them in MP3 - 128khz before copying them on my Walkman through MTP; but enventually all is right.
So I tried to do it in 4 steps :
1. copy / convert files from selected playlists from Media Monkey to my PC
2. copy the converted files manually from the PC to the Walkman
3. export the playlists from Media Monkey to my PC (with the script that allows to export all playlists in .M3U format)
4. copy the playlists files manually from the PC to the Walkman

Now I have big trouble:
- all expected MP3-files are on the walkman
- BUT the playlists aren't converted correctly.

My Walkman can't read them correctly; it seems that the cause is that Media Monkey exports (with the script) the playlists in .M3U in a format that doesn't support all caracters.
In my case, my Walkman stops reading the playlist just before a title containing an " ô " in the name of the file.

What can I do in this case?
Can you:
- correct your script so that all exported playlists are in an encoding format which accept all possible caracters?
- speed up a looot the MTP synchronisation so that all run smoothly, without having this problem?

PS : I try to synch my Walkman, but also smartphone through MTP with a Core i7, 16Mo RAM, with alternatively USB 2 or USB 3, and have since years the same problem. So my computer or my devices aren't the problem ...

Thanks a lot!
Best regards