receivers fail to see attachments even they are attached

[phyrster <phyrster@gmail.com>]

hi,

I use mutt+gmail to send messages and some receivers complaint that there were no
attachments in the message. But I am one hundred percent sure that I have
attached the file. 

The lost attachments only occur when the files' names are in Chinese. If I
rename them into English only names, the attachments then arrive safely. 

What is causing this problem? I guess it is related to either gmail system or
my locale: en_US-UTF-8. But I am not certain what it is and how to slove it. 

My system is Debian/Sid.

-- 
regards
phyrster