So I bought 2GB RAM yesterday and I installed the AppleVIAATA kext from the iPC DVD that is suppose to fix the 4GB RAM issue. Everything was working great at night but today in the morning, my system had crashed.

So now I have also installed the AppleNForce kext early in the morning and will see what happens. Just wanted to post the update just in case if there's something else I need to do which I might have missed.