[Mimedefang] MIMEDefang apparently corrupting TeX files

[boyken at divms.uiowa.edu]

One of our users is reporting that TeX files emailed to him as attachments are
being corrupted.  Equal signs are being replaced by characters that in hex
notation are of the form D followed by a second apparently random hex digit. 
The MIME type is always application/octet-stream.  The problem didn't pop up
until we installed MIMEDefang.  The user has successfully sent the same file to
a different email address.  So, it looks like MIMEDefang is corrupting this
attachment.  If anyone has any idea about what might be going wrong, I'd
appreciate some advice.  The TeX file is created by Scientific Workplace on a
Windows PC and mailed with Outlook.  Our server software is sendmail; we had
been using 8.12.9 when the problem appeared, and now we're running 8.12.10.  The
server runs on HP-UX 11.11.  We have Perl 5.6.1 installed.  mimedefang.pl
-features produces:

MIMEDefang version 2.36

IO::Socket                    : Version 1.26
MIME::Tools                   : Version 5.411 
MIME::Words                   : Version 5.404 
Digest::SHA1                  : Version 2.02
Mail::SpamAssassin            : Version 2.52
Anomy::HTMLCleaner            : missing
File::Scan                    : missing
HTML::Parser                  : Version 3.26
HTML::TokeParser              : Version 2.24
Unix::Syslog                  : Version 0.100

-- 
Karl Boyken, system administrator                         karl-boyken at uiowa.edu
303A MLH, Dept. of Comp. Sci.                  http://www.cs.uiowa.edu/~boyken/
The U. of Iowa, Iowa City, IA  52242   319-335-2730 (voice)  319-335-3668 (fax)