Mystery solved; one other thing happened to my PC on the same day the updates were installed. My TrendMicro PC-cillen subscription expired. After removing the key hotfixes I decided to remove the TrendMicro code next and it solved my problem. I'm using a different antivirus program now. I reinstalled all of the Microsoft hotfixes and it's back to its old rock solid self. I've shut down every unnecessary service and IE add-on and I always get a little nervous that an update will create a new dependency on something I've turned off.