vun, thats a different way to center tskbar icons, I used to do it like this...
create folder under your user account, rename it to (Alt+255), right click taskbar>new toolbar and select the folder without a name, unlock the taskbar and drag the grabber near the systray left, then the one near the start to the right until you have the desired offset and lock the taskbar again. This way it will keep autocentering when you open other things even non pinned. Also if you like you can go back to that nameless folder and go to customize and assign it a blank icon and no one would see that folder if they are browsing in explorer.