When creating video animation using key frames (in FCPX).it auto converts my second key frame to smooth and makes animation drift at that second point.. Why?

Here is scenario.

set first key frame inside viewer window on key frame button...move skimmer to set duration...use inpsector to scale..then reposition on screen moving only center circle....repeat these action two more times...then make it go back to full screen using inspector to make last move go 100 % scale and position 0/0 (by adding keyframes in inspector then changing value of scale and position.

When I play back animation...the second key frame automatically switches to SMOOTH from LINEAR and makes the move "Drift" after it hits key frame.

If I only do the start key frame an the fist animation it stays linear.

why do the frames switch to Smooth if I did not control click and make it happen right on the key frame in the viewer?....I then have to go back and fix the landing to LINEAR to make it work again.


Again I ONLY GRAB THE MIDDLE CIRCLE IN THE VIEWER FOR THE REPOSITION AND USE SCALE IN THE INSPECTOR

THANKS