There is a whole thread about this on ModTheSims2. http://www.modthesims2.com/showthread.php?t=117748&c=1&page=1&pp=25
It seems to be an NVIDIA graphics card problem. I am having the same problem as well and I have yet to solve it. Some people have solved it by adding more RAM. I may go that route.
Also a personal observation... Even though some are having this problem with the Pentium4 most of the people that I have noticed with the "Sims Blue Screen of Death" tend to have an AMD64. (I have an AMD64 3200 with a GeForce 6100) I wonder if that is connected???