fck_config

I am facing a strange problem.
After I made some modifications to fck_config.js
the changes didn't take effect.
I thought at first that perhaps it was a caching problem.
It wasn't, because after restarting the bowser the changes still didn't take effect.
The last experiment I did, was to delete the fck_config.js.
I expected that nothing would work anymore.
Everything worked perfectly.
I suspect that an other file is used instead of fck_config.js.
The strange thing is that there is no other copy of that file in my computer.

Well this bizare problem is rather related to javascript than the editor it self.

I hope someone can help.
Bye