problem to delete a file

[nodamei]

I have a unlocked file like this,

-rwxrwxrwx 1 xxxxx admin 51200 Jul 15 2008 10X10.table.doc

Here are some ways I have tried, but all failed.

1. @terminal log in as owner of this file: rm -rf 10X10.table.doc
rm: 10X10.table.doc: Operation not permitted


2. @terminal log in as owner of this file: sudo rm -rf 10X10.table.doc
Password:
rm: 10X10.table.doc: Operation not permitted


3. @terminal log in as root: rm -rf 10X10.table.doc
rm: 10X10.table.doc: Operation not permitted

4. @terminal log in as owner of this file: sudo chflags -R nouchg 10X10.table.doc then sudo rm -rf 10X10.table.doc
rm: 10X10.table.doc: Operation not permitted

5. @Finder window: locate the file -> press COMMAND+DELETE -> pop a window to type password to allow Finder to make changes -> hear the trash sound ==> the file is STILL THERE!

Why is this file so stubborn to delete????
THANKS A LOT!!!

ps: Under the Disk Utility, I can not click "repair disk permission" for this partition, and it is a gray botton.

 

[nodamei]

solved..

After checking everything, mystery is solved. It turns out all files under one directory can not be deleted. The reason is this folder/directory is locked. After unlock this folder/directory at "Finder" window, I can freely delete files inside this folder.