I avoid the problem by using a 3-button mouse that doesn't have a wheel.

You can also avoid the problem with your settings: Tools + Options + General + Display and in the Tree Manipulation tab: turn OFF the ZOOM ON TREE option (Tree zoom after clicking on any branch). To zoom the tree after you turned off this setting, select the axis in the lower-right corner to activate the tree, zoom the tree, and select the axis again to de-active the tree.