nautilus file copy doesn't preserve nanosecond timestamps

Binary package hint: nautilus

nautilus 1:2.30.1-0ubuntu1.1 in Ubuntu Lucid

When copying files in Nautilus, the low 3 decimal digits in the copy are set to zero. In other words, it only preserves 2-microsecond resolution.

Steps to reproduce:
1. Create a file (on a filesystem supporting nanosecond timestamps) and view its timestamp:
username@host:/dev/shm$ touch original-file
username@host:/dev/shm$ ls --full-time original-file
-rw-r--r-- 1 username username 0 2010-09-19 07:27:56.463178584 +0000 original-file

2. Copy file in Nautilus to the same or another filesystem, and view new file's timestamp
# original-file copied to file-nautilus
username@host:/dev/shm$ ls --full-time file-nautilus
-rw-r--r-- 1 username username 0 2010-09-19 07:27:56.463178000 +0000 file-nautilus

Expected result: New file has exactly the same timestamp. For example, cp --preserve=all works properly:
username@host:/dev/shm$ cp --preserve=all original-file file-cp
username@host:/dev/shm$ ls --full-time file-cp
-rw-r--r-- 1 username username 0 2010-09-19 07:27:56.463178584 +0000 file-cp

Actual result: last 3 digits of copy are 000.