If you are having a problem with objects jumping or snapping, even after you have set your keyboard increments to a low number, this will probably fix your problem.
Start by making sure your Keyboard Increment has been set to a fraction in Edit>Preferences>General
If you are still experiencing object snapping, select the object and then go to View>Snap to Grid and make sure it is disabled.
If you are still experiencing unwanted object snapping restart your computer. If that doesn’t fix it punch your monitor repeatedly.