Motion path scaling?

I have a psd file/layer (a flower) in a 3d composition, it has a motion path on it (position time line) with roaming key frames (not sure if thats the correct term?)

As it travels along the motion path, i want the flower to scale down, and ive done this with key frames on the scale time line, but as it scales down, it is also scaling down my motion path? Any ideas why? I want the motion path to stay the same size constantly.

I know that sometimes with key frames, you get different results depending on which order you apply different values etc. But ive tried adding my scale values before i ad my motion path, but with the same result, a scaling motion path.

Any help is much appreciated.

Cheers
i