Hi NoelCan: 

You wrote ... "And what has the last input have to do with rendering?" 

I don't know. I'm ignoring it. :) 
Earlier you wrote ... "All i need is something for mac..." 
I'm new to poser so I can't offer more information. 

I'm just going to get use to Poser and wait for their up-comming software fix. 

I have ordered Apple's new OS "Snow-Leopard".
I'm not going to install it for a month because rumor has it, Poser or Apple may need to fix compatibility problems (I'll see how other Poser/Snow-Leopard users are doing). 

My point being, in the future (one month) I feel the rendering issue will be improved.
On the 2nd post of this thread I attached condensed notes I copied from the Macintosh Poser 8 Manual that may be helpful.
I learned a lot from the reading process.
I previously moved render sliders that were greatly hindering my render.
At the time I did not understand the major affect of a small change.
It also mentions setting your number of Process Threads (if you haven't experimented with that). 
This may be off your topic so I'll stop now. Good-luck 
M_L_R