I can't seem to get the motion blur to work right when I make animations. I make a movie, the blur part renders, but my figure does'nt... so I get this funky halo where my figure should be. If this helps, I'm running SR3 on a Mac. Since I upgraded primarily for this feature and the set-up lab, I'm really bumming that I can't get this feature to work.

How much blur are you using? A setting of 0.5 or 0.6 will usually suffice for realistic results. Extremely high values, like 4 or 5, might cause what you're describing.

The blur setting doesn't seem to matter, I've tried 0.5, 2.0, and 6.0 they all do the same thing...the blur is correct for where the figure is but the figure itself doesn't render, if I turn the blur option off, "Voila" the figure reappears, maybe its a memory thing (yeah, that's always a good scapegoat)

This is a MAJOR BUG!! in SR3 on the MAC platform!!

I too get an all black movie with a faint outline of the character with 2d motion blur using propack SR3!!
fortunately for me i dont render final animations in poser anyway
but import them into cinema 4DXL 7 that has raytracing and true 3D motion blur

but you should report this to CURIOUS LABS ASAP!!