I cannot remember exactly, but I do think I have to zoom in with a different mouse-klick combo, in order to actually zoom.

I usually press Alt + RMB in worldspace (the word "worldspace" contra "objectspace", something I have taken up, after reading about maya MEL and C++ programming )

I think I have to press Alt + LMB+MMB or something. I do think there is something strange going on, in my maya.