Yeah, I was worried that having 4GB of RAM might cause some issues- I recall people complaining about it a while back. So far no problems.
Again, haven't done any stress testing yet- but I did leave my rig running overnight and it never crashed or nothing.
Anyhow, when I get in from work tonight I plan on testing it with Prime95 for a bit. If it doesn't crash while doing that then... on for some gaming, probably a bit of STALKER.