Magic mouse sensitivity issue

I'm using the Magic Mouse on my MacBook Pro and have an issue with mouse sensitivity. I hold my mouse with my thumb on the left, and all fingers except my pointer finger on the right. My pointer finger hovers above the touch surface of the mouse until needed (not a very ergonomic design, thanks Apple). Anyway, every now and then my finger dips a little too low and just barely brushes the surface and generates a number of "events" that the CAD tool I'm using interprets as a zoom-out. When the brushing accident occurs my display suddenly shrinks down to nothing and I have to zoom in. It happens a lot, and many times I swear my finger didn't actually come in contact with the mouse surface, although it was likely very close. Does BTT have any adjustments for the mouse sensitivity before events are created?