When I copy a file (control-C/control-V) with ACL in nautilus, new file
no longer have acl.

An example, I copied the example.txt file with nautilus in
copy_nautilus.txt :

$ getfacl example.txt
# file: example.txt
# owner: bonnegent
# group: insa-personnel
user::rw-
user:malandain:r--
group::r--
mask::r--
other::r--

$ getfacl copy_nautilus.txt
# file: copy_nautilus.txt
# owner: bonnegent
# group: insa-personnel
user::rw-
group::r--
other::r--

$ cp -a example.txt copy_cp.txt
$ getfacl copy_cp.txt
# file: copy_cp.txt
# owner: bonnegent
# group: insa-personnel
user::rw-
user:malandain:r--
group::r--
mask::r--
other::r--

This bug is tested on Ubuntu 13.04 64bits.