inconsistent logs when displayed on screen / piped to a file

Hello,

I'm trying to use "git log" to generate ChangeLog for a project
recently migrated from CVS.

The problem is that
    git log --summary --stat --no-merges --date=short --decorate=short
behaves differently when the result is displayed on screen and when it
is piped to a file.

For example, running the commands:
    a) git log --summary --stat --no-merges --date=short
--decorate=short e9f65aa976
    b) git log --summary --stat --no-merges --date=short
--decorate=short e9f65aa976 > /tmp/log.txt
would result in two different outputs:

a)

 aquaterm/Docs/gptProtocol.rtf                         |  316
++++++++++++++++++++++++++
 aquaterm/English.lproj/GPTInfoWindow.nib/classes.nib  |   12 +
 aquaterm/English.lproj/GPTInfoWindow.nib/info.nib     |   12 +
 aquaterm/English.lproj/GPTInfoWindow.nib/objects.nib  |  Bin 0 -> 1010 bytes
 aquaterm/English.lproj/GPTInfoWindow~.nib/classes.nib |    4 +
 aquaterm/English.lproj/GPTInfoWindow~.nib/info.nib    |   12 +
 aquaterm/English.lproj/GPTInfoWindow~.nib/objects.nib |  Bin 0 -> 1232 bytes
 aquaterm/English.lproj/GPTWindow.nib/classes.nib      |   13 ++
 aquaterm/English.lproj/GPTWindow.nib/info.nib         |   12 +

b)

 aquaterm/Docs/gptProtocol.rtf                      |  316 ++++++
 .../English.lproj/GPTInfoWindow.nib/classes.nib    |   12 +
 aquaterm/English.lproj/GPTInfoWindow.nib/info.nib  |   12 +
 .../English.lproj/GPTInfoWindow.nib/objects.nib    |  Bin 0 -> 1010 bytes
 .../English.lproj/GPTInfoWindow~.nib/classes.nib   |    4 +
 aquaterm/English.lproj/GPTInfoWindow~.nib/info.nib |   12 +
 .../English.lproj/GPTInfoWindow~.nib/objects.nib   |  Bin 0 -> 1232 bytes
 aquaterm/English.lproj/GPTWindow.nib/classes.nib   |   13 +
 aquaterm/English.lproj/GPTWindow.nib/info.nib      |   12 +


The project where the results could be easily reproduced is the following:
    https://github.com/AquaTerm/AquaTerm
    git://github.com/AquaTerm/AquaTerm.git

It is possible that I screwed up something when importing the project
from CVS. In that case I would be happy if someone could point me out
what exactly I did wrong, and I can still rewrite the history before
the first release of the project using git.

But in any case I find it weird that I get two different outputs.

I would be grateful for any clues or hints about what goes wrong.

Mojca