One of the fundamental problems with Security is that if you change something in your code (anything) you are increasing the risk of a security vulnerability being created and later found.
In Security, the more exposed you are, and the less you change the more likely you are to stay safe. If you don’t expose your code (like Linux does) and on top of it go around changing it and it’s architecture you are asking for trouble.
Nice going MS! When can we expect for a new version of Vista with this fixed?
PS: time to change back to XP dady-o!