I was getting the C Exception errors with the Hydra textures. I dropped those down from 5000x5000 to 4000x4000 and the errors went away, so Poser can handle textures greater than 2048x2048. My system is similar to yours except I only have a GeForce 440MX with 64 MB. It will be interesting to see what it looks like after the patch to see if it looks even better because of the power of 2 thing.