Hi there,
I know this specific problem has been resolved, however I had the same problem and the answers in this thread did not help my specific problem. (I live in a PAL region so 25 fps really is 25 fps)
My problem:
When using a motion tracker the RAM preview showed me a perfectly tracked picture.
However when I rendered the object that used the motion tracker was off by multiple pixels in every direction.
My solution: (probably not the best solution but it worked)
Import the After Effects composition into Premiere (Premiere -> File -> Adobe Dynamic Link -> Import After Effects compostion)and export from there.
This fixed it and the render looks perfect.
I hope someone might find this info usefull.
Bye!