I hope that someone can help me with this problem.
When I export sequence of PNG images(with transparent background) from Poser I always have thin white outline over objects. I thought this is small resolution issue so I used bigger resolution. I use firefly render and NO I DON'T use outline option. After applying bigger resolution render, outline is barely noticeable, but now instead of transparent background there is always full gray background. I use FireFly option render over current shader, not background colour or background image or over black color.

Now when I check exported image properties it says it has 24 bit depth?!
How to switch back to 32 bit depth PNG image???
I have simply doubled resolution output settings, and now I can't fix this.
Anyone have idea?
THANK-YOU!