For what it's worth: I'm using Vue 4 on a Dual G4/450 w/ 640mb's ram & OSX 10.2.8. I have it installed to the Applications directory and I use full on openGL. I've used it both with a Radeon 8500 & Radeon 7500. I have had virtually no problems. I have yet to have one single "freeze". I've had a couple of crashes related to doing things with the atmosphere, but overall the crashes are probably only about 1% or 2% of my Vue usage. Now, that being said... I'm just a straight up Vue user (for now). What that means: I don't import anything, I don't use Poser, I don't do animation. Is your iMac one of the older G3 models or one of the newer G4 models? This could easily be a G3 processor issue as it lacks altivec, etc. Considering it's 500mhz and you're using an ATI Rage 128, I'd assume it's one of the old iMacs that uses the G3. I think minimum specs for Vue 4 are a G4 processor (someone correct me if I'm wrong). It could also be something to do with your Video card not liking the latest OpenGL drivers from Apple? I'm not too sure... On a side note... have you tried out Terragen? I don't like pushing Terragen in the Vue forum but it works great on G3 processors and is rock solid stable. I use it on my 500mhz iBook all the time. Terragen isn't a Vue replacement but it's a lot of fun and magic in it's own way. E.