I don't have Poser 7 and have never seen that particular message. However if it's related to large scenes chances are it's actually an "out of memory" error.

You can fix that by rendering your image in bits and pieces IE: hiding some items and rendering others and then unhide the hidden ones and hide the other ones etc.  Or you can reduce the size of the textures. Many are 4,000 pixels long and when you get loads of those in a scene it uses up lots of memory to try and render them.   With my old computer I used to have to open each texture into Paint Shop Pro and resize them to  no more than  1024 pixels on the longest side.  That helped.

So far as I know your graphic card doesn't make a difference unless you are doing animation or playing those huge MMORPG.  In fact most people over buy their graphic card thinking that they need the newest and most powerful, when in fact the cheapest will work for your average computer user, even thouse who use Poser :)

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi