Can't right click dock icons

First of all hello everyone, this is my first post here in MacRumors Forum.

Been searching for a while all around the forum but none of the old post is helping me to solve the problem.

The thing is that about a month or so I decided to change my dock skin, and just the dock, not any icon in particular. Later on I decided to go back to Leopard's original skin, once I replaced non-original skins with the original ones and had dock reseted by introducing "killall Dock" on terminal, dock successfully reseted and looks like the original one... but somehow since then I can't no longer right-click on any of the icons in it, just can't, now I have to use cmd+Q to exit any of the applications I'm openning from dock. All other dock functions are working perfectly, like size bar and position changing.

The files I replaced/erased are:

scurve-I.png
scurve-m.png
scurve-sm.png
scurve-xl.png

By the way, I tryed using "killall Dock" over and over again after replacing those archives and tryed resseting dock using candybar application, but none of those worked for me so far.

Any thoughts?, this is driving me nuts!

Thanks for your time and sorry for my crappy English writing, waiting for your answers.