Weird mask expand at export


I’m having a problem with mocha if I export my “rotoscoped” clip. If I export it, at some frames an edge appears. It looks like the rotoscoped path expands for a frame or two and then shrinks down again. I’ve checked the time line several times and cannot find any key frames that are causing this “expanding mask”.
please see the image to see how it looks like.
Image: - th_36190_mocha_122_801lo.jpg

the red circle indicates the edge that created by the “expanding mask”. the green one indictates how it should be(this part is actually an other ROTO and track).

Thanks in advance

Thanks for posting this, your image does indeed show an issue. Could you perhaps send me a copy of your project file so that I can investigate the issue.

Please send a copy of the project file to:

I posted the same problem in Motor a while ago.