Return-Path header corrupt in virus reports

[Mike Zanker]

I've noticed that the postmaster virus report always seems to have the 
same corrupt Return-Path header, e.g.

Full headers are:
 Return-Path: <?g>

Is this a bug or my misconfiguration somewhere?

Thanks,

Mike
-- 
Mike Zanker
Northampton, UK
PGP Public Key: pgp at zanker.org