Couldn't find any Tab in the NAS drive which references /etc/fs nor /etc/*auto*.
I not sure if it is just a wording issue, or if I sent you to look in the wrong place. I was suggesting that you look in your Mac's /etc/fstab (if it exists) and any /etc/*auto* (for autofs/automount) files that may exist on your Mac's /etc directory (also know as /private/etc). Not for you to look for those files on the NAS.
If I was just confused by your wording, I apologize.
Tried rebooting in safe mode but came up still.
I find it really strange. What would try to access a NAS even when booted into Safe mode?
Have you ever played with "LoginHooks"?
Can you create a new test user account? If you set that account as the default login account after boot, does the NAS try to mount? The idea is to figure out if this is associated with your account, or if it is something global.
Remember to change your default login account back to your normal account when done.
Maybe BDAqua has some more ideas?
Oh yea. With all this experimentation, are you maintaining good backups? I wouldn't want to suggest something and have it go bad. I do not think I have suggested anything dangerous yet, but as my ideas get more far fetched, you never know.