[exim] Auto-reply and foreign characters

Folks,

are there any known problems with the autoresponder if there are non-english characters in the subject header? I've just seen
the failure -

Expansion of "${if def:h_Subject: {Autoreply: $h_Subject:} {Auto-response}}" in uservacation
transport contains non-printing character 207

The actual subject header was -

Subject: =?iso-8859-7?Q?FW=3A_=CF=E9_=E1=EB=EB=E1=E3=DD=F2_=F3=F4=E7_=E8?==?iso-8859-7?Q?=E7=F4=E5=DF=E1?=

There appears to be a double '=' character in there so I think this is due to a broken client.

Thanks,

Clive McDowell

Information Services
The Queen's University of Belfast