Thanks Juju. Now I know it is a bug too. I used Quicktime Pro and erased the frames in quetion. In fact, my last animation had so many "flashes" that I quit SU, restarted my machine while tossing all chaches and exported it anew. Now I was only left with the flahes at the exact exact transition point which where then easy to erase w/out too much damage to the
animation.
Truth to be told, I keep pondering if I should put money into my SketchUp skills with all
the drawbacks, known bugs and limitations. 😕
Maybe I rather pay for tutoring in an established 3D programm like C4D or something. I still can construct in SU but do animations and rendering in C4D.
Any suggestions anybody?
Thanks
Wolf