That is one of the things I found out through experimentation.  Some hairs that had been fine to render in SR2,1 were suddenly 'radioactive' under SR3!  Since I have a LOT of hair, I almost exclusively use trans-mapped because it usually renders quicker. Under SR3 that is NOT true.  Some render the same, some cripple render times.

Same with some nodes. Reflection raytraced is slow, where the gather node seemed to cripple my machine. (Literally. It hit a patch of Gather and always crashed to the desktop!)  Ray-traced glass sometimes rendered slow, or crippled speed or caused crashes randomly.

Since I didn't want to try to re-invent the wheel with SR3, I had to roll back to SR2,1.  I'm used to what will do which foible in Poser 7 SR2,1,  But SR3 in some ways makes Poser act like a different application altogether,IMO.

I cannot save the world. Only my little piece of it. If we all act together, we can save the world.--Nelson Mandela
An  inconsistent hobgoblin is the fool of little minds
Taking "Just do it" to a whole new level!