FCP X Custom Transition Issue

I'm working with a custom transition created in Motion 5 and it's giving me a really annoying error around the edge of my image. When I apply the transition in FCP, I get a 1 pixel border around the entire image that shows the B-layer edge.

My project is SD 720x486, and so are the custom transitions. In order to create the effect I wish, both the Transition A and Transition B layers in Motion must cover the entire length of the project.

Here you can see (especially at the bottom of the image) this border:


Close up of the border error:


As a test, I created a new transition in Motion only containing a Transition A and B layer without any added layers or effects. The only thing I adjusted from the default Transition project is extend both the A and B layers to cover the entire project length. When I apply this test transition in FCP X, the error still appears, so I'm certain it's not a problem with my media/effects. I've also made sure that all layers in Motion are scaled at 100%.

As of note, the material being edited is 720p material that has been scaled to fit in a SD project.

Any ideas as to what has been causing this problem? I will be happy to clarify anything if you find something confusing. Thanks so much for your help!

Are you getting the same issues with the transitions that come with FCPX in that same project?

What are your Motion render settings and are you able to to post the transition, provide media info, to see if I an replicate the problem?

Double check if you are working with square/non square pixels.
Perhaps FCPX is scaling your transition because of that.
You can try to create a motion transition with your FCPX project resolution.

Sounds like NTSC interlace issue.