Is it overclocked, or do you mean an AthlonXP 2700+? It could well be the graphics card; I've had similar issues with Vue myself. In all honesty though, I tried the same crash-prone scene on my Athlon and on my Centrino, and both ended up crashing on me... but only during rendering. The modelling part worked fine, just excruciatingly slowly due to the polygon count. Hm... maybe I should bug E-on and ask for low-overhead foliage proxies as a future enhancement, sort of MetaMation style from the old LightWave 5.x days. What graphics card do you have? Are the drivers up to date?