The MacFixIt Forums Symantec forum has come up with some workarounds for one issue with Norton Scheduler (a component of both Norton Utilities and Norton AntiVirus) and another specific to Norton AntiVirus.
MacFixIt reader NOrm writes "First, a simple workaround for a Norton Scheduler (LiveUpdate, virus checks, other tasks) issue involving Panther and cache-deletion software (or user commands deleting certain caches). Pasting a short command into the Terminal is an immediate workaround while longer-term fixes are explored.
"See the May 1 postings in the thread on 'Norton Scheduler doesn't run on schedule'"
Second, unchecking a Stuffit Deluxe/Expander preference removes a user distraction that occurs when NAV checks downloaded files that Stuffit is expanding: See April 29 thread on "NAV comes to front".