Broken attachment filenames in Ticket History

Hi,
Does anyone has the same problem as I have? If I send a mail with
ISO-8859-x attachment name, there will be no filename appaering in
ticket history - just a few characters or nothing. I’ve tried to debug
it, and the result is: no real mime header arrives to to sub Create at
Attachment_Overlay.pm. There is some thing, but this is what I’ve sent:
(attachment’s mime header)

Content-Type: image/tiff;
name="=?UTF-8?B?TcOhc29sYXQgLSAyMDQwMDAwMDAwOTgxLnRpZg==?="

Content-Transfer-Encoding: base64
Content-Disposition: inline;
filename="=?UTF-8?B?TcOhc29sYXQgLSAyMDQwMDAwMDAwOTgxLnRpZg==?="

And this is what Attachment_Overlay.pm gets (no content-type):

Content-Type: “Másolat - 2040000000981.tif” Content-Disposition:
“Másolat - 20…”

Any suggestion is welcome,

Ákos Török