I had problems when I installed logitech mouse software on my macbook pro. it switched zoom and up down. (It still did all the same scroll just with different hot keys. I did not like it) I ended up uninstalling the software and just using the mouse without it on my mac. now I still use the logitech mouse with native os x mouse controller set to natural scroll in system preferences. Also I assume you have scroll to zoom checked in poser preferences interface tab.

scroll wheel zooms in and out. shift+scroll moves left right. cmd+scroll moves up down. alt+scroll rotates up and down. alt+shift+scroll rotates left and right.