I would start by removing the Sweetpacks infestation before we try fixing Norton Utilities.
To be sure your system is clean of other things that might accompany Sweetpacks, I would suggest you sign up at one of the free Malware Removal sites below. Do not try to do anything on your own as it could make things harder for the Malware Removal expert at that site to help you. Choose one and stay there until your system is clean.
http://www.bleepingcomputer.com/
http://www.geekstogo.com/forum/
http://www.cybertechhelp.com/forums/
http://forums.whatthetech.com/