I am trying to run mine on an imac G5, 1.6 mhz, 1gig of ram, 160 gig hard drive (mostly empty) with my runtime coming off an external drive,I am pretty sure the video cards are up to date (I just got this puter two months ago.....if they are not, how do I check that?) OSX 10.3.9 (with no plans of buying Tiger any time soon.....and this was NOT a Tiger required application when I bought it, just let me say) I am going to try to do a fresh install on a drive that has never had poser on it all and see if that helps, but other than that I can't think of what may help? I honestly may have sounded grouchy above but I honestly just want a program that works :(