Keyframes tweaks WON'T work when time remapping is applied

Ok, here we go.
Simple example: I just cut the last frame of a .mov clip in my timeline. Then I've changed the speed of this tiny clip to 1%, and stretched it some seconds, let's say, 2 seconds.
I'm trying to apply SIMPLE motion tweaks, as position (go down, in this case). 
It simply doesn't work. 
I've been doing this in FCPX for ages, and apparently the same tweak won't work in Premiere, after you applied any time remapping. 

Is that it?