iMac G5 Video chip sets

I have one of the first generation imac g5 systems. According to the System Profiler, this system has an nVidia Goeforce 5200 video chip set. I just bought aperture 1.5 thinking that it would run on my system ... in the system requirements for Aperture, it says that it supports the nVidia Geoforce 5200 ultra. However, Aperature refuses to run, telling me that I don't have one of the supported chip sets.

I can't find anything on nVidia's web site to help me. Are these in fact different chip sets? If so, can they be upgraded?neye:

Unfortunately you can't upgrade and they are different graphics cards. I was in the same situation.