Sorry for the lack of information!
I am using the latest version of AE.
I am using Particle Illusion and I create an effect and export it out with an alpha channel. I have used PNG, TIFF and AVI progressive
Then I import it into AE with a comp that should match the size, frame rate, progressive etc..
When I export it out as AVI, MP4, MOV I get wavy lines that show up at the bottom of the screen.
If I do not use that particular effect, it seems to be ok. I will try to show a post later.
Thank you.