Is it only doing it between 1 and 2? Any chance it is happening to a lesser degree 2 to 3, 3 to 2 and so on? Does it happen all the time or sporadically?

Experiment: When your VX does this take a look at your dash lights and see if the gear indicators are flickering the wrong gears.

Though it sounds on the surface not to be the mode switch, do a search on the forum for it... see if anyone's experience with hard shifting sounds like your situation.