corrupt Files (binary) after checked in a new Version

Hello
I really got a problem here.
We use a program which creates .acd files. This is a binary file.
If i check it in with vss2005 (Version 8.0.50727.787) then check it
out an check in a modified version, the file gets corrupt and is
unusable.
with a file compare program ,which compares the binary files
textbased, i can see that many ������"small rectangle" are added
to the corrupt file.

i already tried the following hotfixes:
http://support.microsoft.com/kb/915312
http://support.microsoft.com/kb/923434
http://support.microsoft.com/kb/925234
http://support.microsoft.com/kb/927004
http://support.microsoft.com/kb/930573

none of them helped for my problem.

anyone know this problem and can help me?

thanks