Thanks wuischke, I spent a bit of time reading your link and other related found in it.
I understand that the problem is the char set in use on my system, but it's very strange, before, on Ubuntu Dapper, I was using amule CVS from wollstrecker debian repos and I never had this problem. Now I changed to Ubuntu Edgy and I had to switch to trevino repos because the other was not working anymore.
Do I have any chance to switch back to wollstrecker repos?