How is it without the large bg image? If it’s fine without the image, then check your prefs, OpenGL page, and make sure the “do not use texture RAM for bg images” option is checked. If it’s already checked, uncheck it and see if that makes a diff.
If removing bg doesn’t make a difference, I’m not sure what’s going on. You also didn’t verify that you have the latest drivers from NVIDIA. That’s ultra, super, mega important. Old/bad drivers can really make things slow.
Also, what frame number are you working at in particleIllusion. Higher frame numbers cause *much* calculation to be done, as particles need to be calculated from the beginning.
Alan.
http://www.wondertouch.com