@MagnusGreel
The  "working fine" means that your graphics card driver works for the most part. But having Poser (and possibly other software, like many games, that rely on ogl interface) not working with ogl is probably because the driver is lacking some ogl functionalities that Poser needs and such functionalities are currently available in the corresponding NVidia drivers.

Personally I would categorise your problem under a graphics card driver issue and that is also something that can only be addressed by ATI Technologies since Linux programmers are not allowed access to driver specs or programming APIs of new chips thanks in no small part to M$.  It's my understanding that ATI released a new driver only last week so you want to check if that makes you problem disappear.

I don't want to wage any "chipset wars", but simply to offer an explanation of what your problem is possibly related to. Ie. an incomplete driver that doesn't address enough ogl functionalities to satisfy Poser.