Dear captnhook,
I remove the KB891711 just by doing a restore of the "system checkpoint": "update windows v 4". This restore point is automatically taken before the install of KB891711.
The only ad-killing software I am using is POW.EXE and not proxomitron. As already stated: I noticed the problem only when I try to connect to the Internet using ADSL enternet 300 software. I suppose that people suffering from the "blue screen" at StartUp, are doing some kind of direct connection to the internet at StartUp. In the knowledge base from MS I see also that this KB891711 is updated recently: »
www.microsoft.com/techne ··· 002.mspx .
I have also a second machine running WinXP SP2, but this OS does not requires this correction.