Redmine

md5 calculated incorrect for files, that contains "\r\n" on Windows platform.
line:
self.digest = Digest::MD5.hexdigest(File.read(diskfile))
replaced "\r\n" -> "\n" and than calculated checksum

for file in attachment correct md5 is f2789658fd0737100f4dd1fac58c08e9 but redmine calculate it as 37c4b87edffc5d198ff5a185cee7ee09

ruby script/about:
About your application's environment
Ruby version 1.8.6 (i386-mswin32)
RubyGems version 1.3.1
Rails version 2.0.2
Active Record version 2.0.2
Action Pack version 2.0.2
Active Resource version 2.0.2
Action Mailer version 2.0.2
Active Support version 2.0.2
Edge Rails revision rel_2-0-2
Application root C:/Program Files/Ruby/redmine
Environment production
Database adapter postgresql (8.3.4 win i386)