Photoshop CS5 "Your 3D scent now exceeds the limits of lights and/or textures for the video card's hardware?

I run on win xp and have 4Gb of DDR3 RAM and 2 Gb video onboard DDR3 RAM so that's 6Gb all together and the file that I'm using is only 3Mb so I don't really know what the issue is here. When I look in task manager i do see that Photoshop is using 1.2 Gb of RAM and Firefox using about 500Mb of RAM so why does it say my hardware is exceeding the limits? I even have my preferences set to use more than 80% of RAM and I have over 1Tb of hd space that's set to be used some for page filing....this makes NO sense to me :(