[Zope] problem downloading PDF:File does not begin with '%PDF-

[robert rottermann]

Hi there,

for some time (10 days) we have problems downloading PDF-Files from a 
zope site.
It used to work before. The only thing that was done, was updating 
Linux with security updates.
Now we get on windows clients:File does not begin with '%PDF-'
(both with IE6.x, Firebird, Mozilla).
On a Linux client things work fine.

When I change the content-type in the ZMI from

application/pdf
to
application/x-pdf

The file is downloaded and presented in the acrobat reader without glitch.


What we use is:
Zope 2.7
Python 2.3.3
Apache 2
Suse Linux 9.1 (Kernal 2.6)

Can somebody indicate me towards an solution less radical than changing 
all content-types ?

Thanks
Robert