problems of git-status

Hi,
   I find "git status" and "git status ." have different output and the latter
will go wrong in the case below:

#!/bin/sh rm -rf tt; mkdir tt; cd tt

git init mkdir AA echo hello>a git add . echo world>a

echo "different output..." echo "--------------------git status-------------" git status echo "--------------------git status . ----------" git status .

git add a git commit -m "test" echo hello world>a git add a sleep 4 echo world hello>a echo "--------------------git status-------------" git status echo "--------------------git status . ----------" git status .

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

I use git version 1.5.1.rc2.15.g465b3, "git repo-config -l" shows:
	core.filemode=false
	core.logallrefupdates=true
	core.compression=9
	diff.color=auto
	pack.window=64
	merge.summary=true
	core.repositoryformatversion=0
	core.filemode=false
	core.bare=false

Here is the output of that script:

Initialized empty Git repository in .git/
different output...
--------------------git status-------------
# On branch master
#
# Initial commit
#
# Changes to be committed:
#   (use "git rm --cached <file>..." to unstage)
#
#	new file: a
#
# Changed but not updated:
#   (use "git add <file>..." to update what will be committed)
#
#	modified:   a
#
--------------------git status . ----------
# On branch master
#
# Initial commit
#
# Changes to be committed:
#   (use "git rm --cached <file>..." to unstage)
#
#	new file: a
#
Created initial commit dc57cb444335e73ce3320c1e368765b1a92e3be5
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 a
--------------------git status-------------
# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#	modified:   a
#
# Changed but not updated:
#   (use "git add <file>..." to update what will be committed)
#
#	modified:   a
#
--------------------git status . ----------
fatal: Entry 'a' not uptodate. Cannot merge.