[Mailman-i18n] Problem with header encoding on 2.1.9 - any ideas?

Hi there, I have a problem with MailMan and Japanese ISO-2022-JP encoding. When a header includes a ";" as part of the ISO-2022-JP encoding, MailMan seems to replace it with "; " (note the extra space). This messes up the characters. Real-life example: Original: Subject: =?ISO-2022-JP?Q?607716139:_=1B$B%a%C%;!<%8%m%1!< %=3FF0:nIT6q9g=1B(B?= Mailman-sent: Subject: =?ISO-2022-JP?Q?607716139:_=1B$B%a%C%; !<%8%m%1!< %=3FF0:nIT6q9g=1B(B?= I tried looking at the code, but I couldn't figure it out and so I'm asking here first before I dig deeper. Does anybody know what might cause this? Thanks! Wout.