Shortcuts for Tumble and Track replaced by dolly-zoom.

[CassieAnimates]

Whenever I try to orbit or use the track tool, I end up zooming in or out.

After resetting preferences several times, I can't get my head arounds this. It started with the tumble tool and track still working with their shortcuts (Alt+LMB and Alt+MMB as normal) most of the time, with the zoom tool suddenly popping up instead. Now all three mouse buttons seem to be assigned to Dolly-Zoom. I have to pull out the Camera Tool panel to click between them manually, without the shortcuts. But it's slowing down my workflow. 

Does anyone have any ideas?