NT administrators and client support personnel are learning that you can not be too cautious about reapply NTs service pack after an application upgrade. If you get mixed NT system executables, it can result in a wide range of symptoms varying for odd, sporadic problems to total failure. The best rule of thumb to follow is to reapply the service pack any time NT requires you to reboot. That is, the all too common:

Changes have been made, you must shutdown and restart your computer ..."

Never skip the reapplication at this point. To be very conservative, reapply after installing any software package.