Could be wrong, but I don't think this has anything to do with SU?
If I turn my laser mouse sideways and move it vertically, the pointer moves sideways, regardless of the program.
On that note, one of the things that makes SU easier to use with a mouse in my experience, even easier than many other programs, is its geometric analysis inference engine.
For instance, in line drawing the linear inference will automagically move between snapping a new line on axis, from point, perpendicular, parallel, or tangent to the vertex.
This is real handy for the non pro's like me, particularly when drawing in 3D.
On most CAD programs I've used in the past I've had to periodically set a parameter/hold a key down to get that ability, even in 2D.