Comment 1 for bug 578720

It looks like I have the same problem.
I'm using
Ubuntu 10.04 LTS Server Edition
redmine 0.9.3-1 with mysql

It looks strange, like the content get's mixed up after some buffer is used.

I've added 2 files.
Test.pdf - the file created by copy&paste of random content
and
Test_download.pdf - The same file after downloading it from a ticket.