First post for me here (probably not the last one

I just bought the plugin last week and start learning and experimenting with this awesome plugin.
I got something i can't figure it out.
I just installed the last version of the plugin 3.0 Alpha 10.1(OSX)
It seems i got some alpha appearing in some frames in the rendering. (actually always at least 1 frame) it already has been the second one, here is the third one. It looks a bit random.
I just use a c4d shader as texture background and allow alpha.
Is this a bug with the version ? or did i miss something ?

Thx for your feedback and congratulations for the hard work.
Can't wait to have the final version in hands :-p
++