Hi Ronald, if I understand you correctly that is an intentional feature - holding down Alt and doing a left click and drag does camera manipulation in the 3D viewport, that's another possible way to do it in addition to just plain right button drag, I added that in because there are several programs that do viewport manipulation that way (with Alt, Shift+Alt, or Ctrl+Alt and left drag) and so having that in addition to the regular ways tends to make MoI just a little more friendly to people who are mostly used to some other program.

If you want to disable snapping for doing a drag, push Alt _after_ you have started the drag instead of holding it down before the drag.

- Michael