This has been bothering me for years. From distribution to distribution and from version to version, it still remains.

If a client sends me an e-mail with a file attachment, it opens with a normal double-click as long as the filename has only characters like A-Z and 0-9, etc.

But when the attached filename contains one of the following characters, it won't open or Thunderbird messes up the characters while passing them as a parameter to OpenOffice.org, GIMP or Firefox for example, causing an error message in the associated program:

Problematic characters: ä, ö, ü

I can save the file manually and then open it from Konqueror without issues. But what can I do to make it work with a double-click from Thunderbird? This is what I've tried in the several years struggling with this:

- tried various encodings (including UTF-8) for the filesystem of the tmp-folder, where Thunderbird saves the attachment temporarily, passed the encoding as an option in /etc/fstab
- tried to export various encodings (including UTF-8) before running Thunderbird
- went through every single Thunderbird setting to find the settings for message encoding, nothing seems to help

Is it even an encoding issue? What could I still try?