Xbuntu / AMD
Short description of error
If you key a pose and then move that key in the dopesheet editor, the pose doesn't update (until you do something like changing the color of a keyframe which updates everything).
Exact steps for others to reproduce the error
You'll need the viewport and dopesheet editor
Select the cube and key the location
Scrub to frame 10
Move the cube to another position and key the location
Scrub to frame 4 and key the location
Grab the key on frame 4 and move it to frame 20
...Scrub between all the frames and you'll see it hasn't updated (it ignores the key that's on frame 20)...
Now change the color of any key (by hitting R) and everything has updated properly