It seems that many have issues with p7 and opengl, but in many different ways...
My own problem is quite specific and deadly: if I start P7 and load a figure while being on opengl preview settings, my software inevitably crashes. Vista tells me that Poser has ceased functionning and that i can either send a report or go beeeep myself and go back to desktop.
I am running a 2gb of ddr2 on a quad core cpu and vista ultimate 32 bits. My driver is the very latest from nvidia and makes no difference with the prior one.

Any suggestions are extremely welcome x_x 

nvidia has released many different versions of drivers.. you might need to go back a few months to get a properly working one. Ati's drivers have been screwed up with opengl since decemeber last year.

Also, do you have the latest update to poser 7 installed? Is hardware acceleration turned on?

I can only load so many objects - at a certain point, if I have too many objects in a scene, opengl goes completely wack.  Switching to the alternative display mode is probably the best solution for now.

Hey you know what eliminates that is if you rotate the camera a little bit before loading anything.
Works for me. I had that problem with P7, Vista Ultimate x64, and the latest 64 bit Nvidia Vista drivers. It's almost like poser needs to be "primed" or something. Weird, but that's the only way I can keep it from crashing. After that, it'll run forever without a problem.
There's also some hack for entering a different value in the Poser.ini file which might help, although for the life of me right now I can't remember what it is.

I don't think Poser is the issue, since it works fine under XP. It's more likely between Vista and OpenGL, they may not play together well. Not suprisingly at all, since Microsoft rather not support OpenGL at all.

I use several apps which are far more demanding on the OpenGL than Poser is and have no problems at all with the exception of one teeny little bug with one tool in LightWave Modeler.
Although it probably is a Vista thing, it's more like a combination of Poser and Vista and OpenGL, not just Vista.
I do have the same problem in XP x64 with the same card, and the latest Poser 7 with the latest patches and updates. It didn't happen prior to installing the latest Poser 7.2.something patch.