Teddy, this is odd because I haven't had this problem. I also have a dual core with 2 gig ram. I don't defrag and compact my databases often but seems to be running pretty smooth and rarely lags.
That's why I was a little surprised when a friend of mine had the same problem with crashing. He's running vista and has set up the exe as administrator. I think he sorted out some of the problems, he talked about it on this post
Here