To make it permanent just do the old steps then:-
- [ options + i ] @
- Change "Ownership & Permissions" to "Read Only".
- Tick on the "Locked" box under "General".
There, you're done!
Menufela seems to be updating that .plist file so I thought if it's possible to force the program not to update that file while it still has access then it won't have any problem so I figured out to manipulate with its Permissions and I tell you, after around 2 hours of experimenting, rebooting and reading further info on changing permissions, it worked!
The funny part is that I was trying so hard to update that file's permissions using
chmodcommand in Terminal by following instructions on my O'Reilly book but then I thought to myself "Wait a sec! I can change it easily using File Info!!". lol.
Ok I admit that was stupid but at least I came up with the solution and that what really counts, right? ;P