git and filesystem problems (ext3 and vfat)

Hello, ]

 I have a diskOnKey which has a vfat filesystem.
I ran there:
git clone git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6.git
the I copied all the wireless-2.6 folder to an ext3 partition.
There I ran git diff.

I get many messages like these (probably on all files of the repository):

diff --git a/COPYING b/COPYING
deleted file mode 100644
index ca442d3..0000000
--- a/COPYING
+++ /dev/null

@@ -1,356 +0,0 @@
-

and then all the lines of the file with "-" in the beginning, as if
they are empty.

Why is it so ?
Is there any way to overcome it ?
Must I run "git clone" on an ext3 DiskOnKey only ?

Regards,
Ian