OK i've made a workaround. No transition between flash and jpg, - check!
But I still got the problem with a black blink/flicker in the switch from flashani to jpg
I have: jpg, jpg, jpg, jpg, flash, jpg... The background in SF3 is all white, the background in flash is white and I even have a white image filling the scene. I put in a "stop" action in the last frame in the flashani to break out of the loop (only way, it seems) and it stop ok and moves on to the next jpg (without crossfade-transition,- it's ok) but with one short black blink/flicker. If I make the flashani smaller than the screen and set it to "Do not change size" it's only the area used but the flashani that blinks.
So basically I still have trouble mixng flash and jpg's.
I'm on Windows XP, Flash MX (6) nice new monitor and graphicscard so that should be ok.
Any ideas?