Pilou,

thanks, hope you wont be mad at me but the center tool is actually the reset button and it behaves differently depending on if objects are selected or not (see Moi docs). When an object is selected and the reset button is clicked ounce, it will zoom the object to its extents and center in the viewport and if we 3D rotate the viewport, all movement are in relation to the center of the object but the option setting must be set to rotate around world Z or the free rotation setting. This works only when a single object is selected.

When no objects or multiple objects are selected 3D rotate behave kind of normal ie. around the world Z.

I either forgotten this or possibly I didn't know about it, so it worked like I wanted only by accident more then by choice.

I just hope I wont forget this in the future.

Thanks,
Felix