Alpha Problem in FCP X that docent happen in FCP 7

I have a graphic that was created in After Effects with alpha premultiplied and exported as a ProRes 4444. I import the graphic in FCP X and I add a black generator and as a connected clip I add the After Effects with alpha premultiplied graphic and it's not doing a good job, as you can see in the still that I include (FCP X.jpg) the colors are different, the quality it is like low resolution and it have a hallo. If I change the alpha handling to None/Ignore Alpha it is like it's suppose to be and with good quality so I suppose that the problem is with the Alpha.

I also did the same test in FCP 7 a black generator track 1 and in track 2 I add the After Effects graphic with alpha premultiplied graphic and I don't have the problem with the Alpha. I also include a still (FCP 7.jpg).

So any help would be appreciated way in FCP 7 is OK and in FCP X don't work.

Thanks,
Ricky Dominguez
Luna Films
Puerto Rico